The Hebrew calendar (Hebrew: הלוח העברי‎) or Jewish calendar is a lunisolar calendar used by Jews for predominantly religious purposes. This article is about the Vietnamese holiday For the 1968 military operation that began on that holiday see Tết Offensive. By the traditional Xhosa calendar, the year began in June and ended in May when Canopus, a large star visible in the Southern Hemisphere, signalled the The Zoroastrian calendar is a religious Calendar used by members of the Zoroastrian faith and it is an approximation of the (tropical Solar calendar. The Runic calendar is a Perpetual calendar based on the 19 year long Metonic cycle of the Moon Mesoamerican calendars are the calendrical systems devised and used by the Pre-Columbian cultures of Mesoamerica. In the Mesoamerican calendars, Calendar Round dates are composed by interlacing the dates of a 260-day period ( Tzolk'in in the Maya Calendar, Tonalpohualli The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita The Calendar of saints is a traditional Christian method of organizing a Liturgical year on the level of days by associating each day with one or more Saints The Eastern Orthodox liturgical calendar describes and dictates the rhythm of the life of the Eastern Orthodox Church. The liturgical year, also known as the Christian year, consists of the cycle of liturgical seasons in Christian churches which determines when The Darian Calendar is a proposed system of time-keeping designed to serve the needs of any possible future human settlers on the planet Mars. The Discordian or Erisian calendar is an alternative Calendar used by some adherents of Discordianism. A perpetual calendar is a Calendar which is good for a span of many years such as the Runic calendar. A wall calendar is a Calendar intended for placement on a wall Economic calendar is a type of Calendar that is intended to inform financiers and traders about the scheduled major economic numbers (like CPI, A lunisolar calendar is a Calendar in many Cultures whose date indicates both the Moon phase and the time of the solar Year. PLEASE TAKE NOTE************ It is used to reckon the Jewish New Year and dates for Jewish holidays, and also to determine appropriate public reading of Torah portions, Yahrzeits (dates to commemorate the death of a relative), and daily Psalm reading, among many ceremonial uses. For the Gregorian dates of Jewish Holidays see Jewish holidays 2000-2050. Torah reading ( is a Jewish religious Ritual that involves the public reading of a set of passages from a Torah scroll. This article is about the divisions of the Torah into weekly readings Bereavement in Judaism ( is a combination of Minhag (traditional custom and Mitzvot (good deeds or religious obligation derived from Judaism 's classical Psalms ( Hebrew: Tehilim, תהילים, or "praises" is a book of the Hebrew Bible (the Christian Old Testament) included Originally the Hebrew calendar was used by Jews for all daily purposes, but by the era of the Roman occupation (1st century BCE), Jews followed the imperial civil calendar for all civic matters, such as the payment of taxes and dealings with government officials. Kingdom of Judea redirects here For the 10th-6th century BCE kingdom see Kingdom of Judah Iudaea ( Hebrew: יהודה Standard The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita

The principles of the Hebrew calendar are found in the Torah, which contains several calendar-related commandments, including God's commandment during the Exodus from Egypt to fix the month of Nisan as the first month of the year. term " Torah " ( Hebrew: תּוֹרָה "teaching" or "instruction" sometimes translated as "Law" most commonly refers to This article is about commandments in Judaism For the Jewish rite of passage see Bar Mitzvah and Bat Mitzvah Mitzvah ( Hebrew: מצוה Exodus ( Greek: έξοδος eksodos = "departure" is the second book of the Jewish Torah and of the Christian Old Testament. This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer ^[1] The Babylonian exile in the 6th century BCE influenced the calendar, including the adoption of Babylonian names for the months. The Babylonian captivity, Babylonian exile, is the name typically given to the deportation and exile of the Jews of the ancient Kingdom of Judah to Babylon was a City-state of ancient Mesopotamia, the remains of which can be found in present-day Al Hillah, Babil Province, Iraq ^[2]

Before the destruction of the Second Temple in 70 CE, the calendar was observational, with the beginning of each month determined by the testimony of witnesses who had observed a new crescent moon. The Siege of Jerusalem in the year 70 AD It was a decisive event in the First Jewish-Roman War, followed by the fall of Masada in 73 The Second Temple (בית המקדש romanized 'Beit HaMikdash' meaning 'Holy House' was the reconstructed Temple in Jerusalem which stood between 516 BCE and 70 CE Lunar phase (or Moon phase refers to the appearance of the illuminated portion of the Moon as seen by an observer usually on Earth Between 70 and 1178 CE a rule-based fixed-arithmetic lunisolar calendar system was adopted to achieve the same effect. A lunisolar calendar is a Calendar in many Cultures whose date indicates both the Moon phase and the time of the solar Year. The principles and rules of the current calendar were fully described by Maimonides in 1178 CE in the Mishneh Torah. Moses Maimonides ( March 30 1135 – December 13 1204) also known as the Rambam, was a Rabbi, Physician, and The Mishneh Torah ( Hebrew: משנה תורה subtitled Sefer Yad ha-Chazaka (יד החזקה is a code of Jewish Religious law

Because of the roughly eleven-day difference between twelve lunar months and one solar year, the year lengths of the Hebrew calendar vary in a repeating 19-year Metonic cycle of 235 lunar months, with an intercalary lunar month added every two or three years, for a total of 7 times per 19 years. In Lunar calendars a lunar month is the time between two identical syzygies ( New moons or Full moons. A tropical year (also known as a solar year) is the length of time that the Sun takes to return to the same position in the cycle of seasons as seen from Earth Metonic cycle or Enneadecaeteris in Astronomy and Calendar studies is a particular approximate common multiple of the Tropical year Intercalation is the insertion of a leap day week or month into some calendar years to make the calendar follow the seasons or moon phases Seasonal references in the Hebrew calendar reflect its development in the region east of the Mediterranean Sea and the times and climate of the Northern Hemisphere. Northern Hemisphere is the half of a Planet that is North of the Equator —the word hemisphere literally means 'half ball' With respect to the present-day mean solar year, the Hebrew calendar's year is longer by about 6 minutes and 25+²⁵/₅₇ seconds, meaning that every 224 years, the Hebrew calendar will fall a full day behind the modern fixed solar year, and about every 231 years it will fall a full day behind the Gregorian calendar year. This is due to the 0. 6 second discrepancy between the calendric "Molad" (lunar conjunction interval), which is fixed by Jewish Law,^[3] and the actual mean lunar conjunction interval, which itself is slowly changing over time. Molad (plural Moladot) is a Hebrew word meaning "birth" that also generically refers to the time at which the New Moon is "born" Halakha ( הלכה; alternative transliterations include Halocho and Halacha) is the collective body of Jewish Religious law ^[4]

Years in the Hebrew calendar are labeled with the era designation Anno Mundi (Latin: "in the year of the world", abbreviated AM or A. An era is a commonly used word for long period of time When used in science for example geology eras denote clearly defined periods of time of arbitrary but well defined la Anno Mundi (Latin "in the year of the World " abbreviated as AM or A Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. M. ) and are numbered from the epoch approximately a year before Creation. In the fields of Chronology and Periodization, an epoch means an instant in time chosen as the origin of a particular Era. Cultures throughout history have believed the world formed or was formed at some time in the past so methods of dating Creation have involved analysing scriptures and some physical The current Hebrew calendar year is 5768.

Structure

The Jewish calendar is a lunisolar calendar, or "fixed lunar year," based on twelve lunar months of twenty-nine or thirty days, with an intercalary lunar month added seven times every nineteen years (once every two to three years) to synchronize the twelve lunar cycles with the slightly longer solar year. A lunisolar calendar is a Calendar in many Cultures whose date indicates both the Moon phase and the time of the solar Year. In Lunar calendars a lunar month is the time between two identical syzygies ( New moons or Full moons. Intercalation is the insertion of a leap day week or month into some calendar years to make the calendar follow the seasons or moon phases A tropical year (also known as a solar year) is the length of time that the Sun takes to return to the same position in the cycle of seasons as seen from Earth Each Jewish lunar month starts with the new moon; although originally the new lunar crescent had to be observed and certified by witnesses, the timing of the new moon is now mathematically determined. This article is about the lunar phase for other uses see New Moon (disambiguation.

Concurrently there is a weekly cycle of seven days, mirroring the seven day period of the Book of Genesis in which the world is created. The names for the days of the week, like those in the Creation story, are simply the day number within the week, with Shabbat being the seventh day. Shabbat or Shabbos ( Hebrew: שַׁבָּת, shabbāt, shabbes, "rest/inactivity" is the Weekly Sabbath The Jewish day runs from sunset to the next sunset, and accordingly, standard times and time zones have no place in the Jewish calendar. Standard time is the result of synchronizing clocks in different geographical locations within a Time zone to the same time rather than using the local meridian as

The twelve regular months are: Nisan (30 days), Iyar (29 days), Sivan (30 days), Tammuz (29 days), Av (30 days), Elul (29 days), Tishrei (30 days), Cheshvan (29 or 30 days), Kislev (29 or 30 days), Tevet (29 days), Shevat (30 days), and Adar (29 days). This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer Iyar ( Hebrew: אִייָר or אִיָּר, Standard Iyyar Tiberian ʾIyyār; Sivan ( Hebrew: סִיוָן, Standard Sivan Tiberian Sîwān; from Akkadian Av ( Hebrew: אָב, Standard Av Tiberian ʾĀḇ; from Akkadian abu Elul (אֱלוּל Standard Elul Tiberian ʾĔlûl; from Akkadian elūlu) is the twelfth Tishrei (or Tishri) (ˈtɪʃri or) ( Hebrew: תִּשְׁרֵי‎ ( תִּשְׁרִי‎) Standard Tišre Cheshvan ( Hebrew: חֶשְׁוָן, Standard Ḥešvan Tiberian Ḥešwān) short for For the Warhammer Fantasy location see Kislev (Warhammer Kislev ( Hebrew: כִּסְלֵו, Standard Tevet ( Hebrew: טֵבֵת, Standard Tevet; Ashkenazi Teves; Tiberian Shevat (or Shvat) ( Hebrew: שְׁבָט, Standard Šəvat Tiberian Šəḇāṭ Adar ( Hebrew: אֲדָר, Standard Adar Tiberian ʾĂḏār; from Akkadian In the leap years an additional month, Adar I (30 days) is added after Shevat, and the regular Adar is referred to as "Adar II".

The first month of the year is Nisan. The 14th of Nisan is the start of the festival of Pesach, corresponding to the full moon of Nisan. Passover ( Hebrew, Yiddish: פֶּסַח Pesach, Tiberian: pɛsaħ Israeli: Pesah, Pesakh, Yiddish Full moon is a Lunar phase that occurs when the Moon is on the opposite side of the Earth from the Sun. Though it is not expressly prescribed in these terms, Pesach is a spring festival, so the 14th of Nisan is the first full moon after the vernal equinox. An equinox is the event of the Sun passing over the Earth's equator in its annual cycle Therefore, from the standpoint of determining the annual calendar cycle, the principal problem is that the lunar month/new moon of Nisan must occur before the spring equinox. Since at least the 12th Century, the Hebrew calendar has determined this time mathematically, but prior to this tradition held that the 1st of Nisan does not start (and an intercalary month would be added) until the barley is ripe. Intercalation is the insertion of a leap day week or month into some calendar years to make the calendar follow the seasons or moon phases ^[5]

While the bible designates this month (without calling it Nisan) as the first month of the year, Rosh Hashanah, which is literally "The Head of the Year", meaning "The Beginning of the Year", is actually celebrated on the first of the seventh month, currently called Tishrei, so most Jews today view Tishrei as the de facto beginning of the year. This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish Tishrei (or Tishri) (ˈtɪʃri or) ( Hebrew: תִּשְׁרֵי‎ ( תִּשְׁרִי‎) Standard Tišre Although there are references to this holiday in the Torah, it was not then regarded as the beginning of the year, but more as a Holiday for reflection and remembrance. term " Torah " ( Hebrew: תּוֹרָה "teaching" or "instruction" sometimes translated as "Law" most commonly refers to

Sources and history

The Torah contains several commandments related to the keeping of the calendar and the lunar cycle. See also Mitzvah See also Biblical law in Christianity The 613 Mitzvot ("commandments" (also " 613 Mitzvos

Day

The day is the smallest unit in the Jewish calendar. It is modeled on the Creation story and is of no fixed length. Creation according to Genesis refers to the Hebrew narrative of the creation of the heavens and the earth as told in chapters 1 and 2 of Genesis Based on the reference to ". . . there was evening and there was morning. . . "^[6], the Jewish day runs from sunset (start of "the evening") to the next sunset. There is no clock in the Jewish scheme, so that a civil clock is used. Though the civil clock incorporates conventions such as time zones, standard times and daylight saving, these have no place in the Jewish scheme. Standard time is the result of synchronizing clocks in different geographical locations within a Time zone to the same time rather than using the local meridian as Daylight saving time ( DST The civil clock is used only as a reference point - in expressions such as: "Shabbat starts at . . . ". The steady progression of sunset around the world and seasonal changes results in gradual time changes from one day to the next based on observable astronomical phenomena (the sunset) and not on man-made laws and conventions. Instead of the international date line convention, the antimeridian of Jerusalem is used. The 180th meridian or antimeridian is the meridian defined as 180° longitude (Jerusalem is just over 35° east of the prime meridian). The Prime Meridian is the meridian (line of Longitude) at which longitude is defined to be 0°

Weeks

A bronze Shabbat candlestick holder made in Israel in the 1940s. For a topic outline on this subject see List of basic Israel topics.

The Hebrew calendar follows a seven-day weekly cycle, which runs concurrently but independently of the monthly and annual cycles. The names for the days of the week are simply the day number within the week. In Hebrew, these names may be abbreviated using the numerical value of the Hebrew letters, for example יום א׳ (Day 1, or Yom Rishon (Hebrew: יום ראשון):

Yom Rishon (Hebrew: יום ראשון), abbreviated יום א׳ = "first day" = Sunday
Yom Sheni (יום שני), abbr. The system of Hebrew numerals is a quasi-decimal alphabetic Numeral system using the letters of the Hebrew alphabet. יום ב׳ = "second day" = Monday
Yom Shlishi (יום שלישי), abbr. יום ג׳ = "third day" = Tuesday
Yom Reviʻi (יום רבעי), abbr. יום ד׳ = "fourth day" = Wednesday
Yom Ḥamishi (יום חמישי), abbr. יום ה׳ = "fifth day" = Thursday
Yom Shishi (יום ששי), abbr. יום ו׳ = "sixth day" = Friday
Yom Shabbat (יום שבת or more usually שבת - Shabbat), abbr. יום ש׳ = "Sabbath day (Rest day)" = Saturday

The names of the days of the week are modeled on the seven days mentioned in the Creation story. Creation according to Genesis refers to the Hebrew narrative of the creation of the heavens and the earth as told in chapters 1 and 2 of Genesis For example, Gen 1:5 ". . . And there was evening and there was morning, one day". "One day" also translates to "first day" or "day one". Similarly, Gen 1:8, Gen 1:13, Gen 1:19, Gen 1:23, Gen 1:31 and Gen 2.2.

The Jewish Shabbat has a special place in the Jewish weekly cycle. There are many special rules which relate to the Shabbat, discussed more fully in the Talmudic tractate "Shabbat". Shabbat or Shabbos ( Hebrew: שַׁבָּת, shabbāt, shabbes, "rest/inactivity" is the Weekly Sabbath This is about part of the Talmud; for the Jewish day of rest see Shabbat.

In Hebrew, the word "Shabbat" (שַׁבָּת) can also mean "(Talmudic) week",^[7] so that in ritual liturgy a phrase like "Yom Reviʻi bəShabbat" means "the fourth day in the week". ^[8]

Importance of Lunar Months

Num 10:10 stresses the importance of the new moon and consequently lunar months, ". . . in your new moons, ye shall blow with the trumpets over your burnt-offerings,"^[9]. Similarly in Num 28:11.

In his work Mishneh Torah, of 1178, Maimonides included a chapter "Sanctification of the New Moon," in which he discusses the calendrical rules and their scriptural basis. The Mishneh Torah ( Hebrew: משנה תורה subtitled Sefer Yad ha-Chazaka (יד החזקה is a code of Jewish Religious law He notes,

"By how much does the solar year exceed the lunar year? By approximately 11 days. Therefore, whenever this excess accumulates to about 30 days, or a little more or less, one month is added and the particular year is made to consist of 13 months, and this is the so-called embolismic (intercalated) year. For the year could not consist of twelve months plus so-and-so many days, since it is said: throughout the months of the year (Num 28:14), which implies that we should count the year by months and not by days. "^[10]

Months

Mosaic pavement of a zodiac in the 6th century synagogue at Beit Alpha, Israel.

Biblical references to the pre-Jewish calendar include ten months identified by number rather than by name. In parts of the Torah portion Noach (Noah) (specifically, Gen 7:11, Gen 8:4-5, Gen 8:13-14) it is implied that the months are thirty days long. This article is about the divisions of the Torah into weekly readings This article is about the Torah portion "Noach" For the Biblical figure see Noah. ^[11] There is no indication as to the total number of months in the annual cycle.

In the parts of the Tanakh (the Hebrew Bible) prior to the Babylonian exile, only four months are named: Aviv (first; literally "spring", which originally probably meant "the ripening of barley"), Ziv (second; literally "light"), Ethanim (literally "strong" in plural, perhaps referring to strong rains) I Kings 6:38: seventh month; and Bul I Kings 6:38: eighth month. See also Old testament, Septuagint, Targum, Peshitta The Tanakh (תַּנַ"ךְ (taˈnax or; also Tenakh or Tenak is The term Hebrew Bible is a generic reference to those books of the Bible originally written in Biblical Hebrew (and the related Biblical Aramaic This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer Iyar ( Hebrew: אִייָר or אִיָּר, Standard Iyyar Tiberian ʾIyyār; Tishrei (or Tishri) (ˈtɪʃri or) ( Hebrew: תִּשְׁרֵי‎ ( תִּשְׁרִי‎) Standard Tišre The Books of Kings ( Sefer Melachim, ספר מלכים are a part of Judaism 's Tanakh, the Hebrew Bible. Bul may refer to Cheshvan, a Hebrew month Buol Island, Indonesia Bul, a Mayan board game The Books of Kings ( Sefer Melachim, ספר מלכים are a part of Judaism 's Tanakh, the Hebrew Bible. All of these are Canaanite names, and at least two are Phoenician (Northern Canaanite). Canaanites redirects here For the 1940s social and political movement in Israel, see Canaanites (movement. Phoenicia ( Phoenician: Phoenician nunsvg|12px|נ]]Phoenician nun

According to the Book of Exodus, the first commandment the Jewish people received as a nation was to determine the new moon: Exodus 12:2 states, "This month [Nisan] is for you the first of months. Exodus ( Greek: έξοδος eksodos = "departure" is the second book of the Jewish Torah and of the Christian Old Testament. This article is about the lunar phase for other uses see New Moon (disambiguation. " Deut 16:1 refers to a specific month: "Observe the month of Aviv (HE: spring), and keep the passover unto the LORD thy God; for in the month of Aviv the LORD thy God brought thee forth out of Egypt by night. "

During the Babylonian exile, which started in 586 BCE, Jews adopted Babylonian names for the months, which are still in use. The Babylonian captivity, Babylonian exile, is the name typically given to the deportation and exile of the Jews of the ancient Kingdom of Judah to Babylon was a City-state of ancient Mesopotamia, the remains of which can be found in present-day Al Hillah, Babil Province, Iraq The Babylonian calendar also used a lunisolar calendar, derived from the Sumerian calendar. The Babylonian calendar was a Lunisolar calendar with years consisting of 12 Lunar months each beginning when a new crescent moon was first sighted low The Babylonian calendar was a Lunisolar calendar with years consisting of 12 Lunar months each beginning when a new crescent moon was first sighted low

Hebrew names and romanized transliteration may somewhat differ, as they do for כסלו / Kislev or חשוון / Marheshvan: the Hebrew words shown here are those commonly indicated e. g. in newspapers.

In a short (chaser) year, both Kislev and Cheshvan have 29 days. Adar ( Hebrew: אֲדָר, Standard Adar Tiberian ʾĂḏār; from Akkadian Adar ( Hebrew: אֲדָר, Standard Adar Tiberian ʾĂḏār; from Akkadian In a regular (kesidran) year, Kislev has 29 days and Cheshvan has 30 days. In a full (maleh) year, both Kislev and Cheshvan have 30 days.

The calendar rules have been designed to ensure that Rosh Hashanah does not fall on a Sunday, Wednesday or Friday. This is to ensure that Yom Kippur does not directly precede or follow Shabbat, which would create practical difficulties, and that Hoshana Rabbah is not on a Shabbat, in which case certain ceremonies would be lost for a year. Yom Kippur (יוֹם כִּפּוּר ˈjɔm kiˈpur also known in English as the Day of Atonement, is the most solemn and important of the Jewish holidays Its Shabbat or Shabbos ( Hebrew: שַׁבָּת, shabbāt, shabbes, "rest/inactivity" is the Weekly Sabbath The seventh day of the Jewish holiday of Sukkot, 21st day of Tishrei, is known as Hoshana Rabbah ( Aramaic: הוֹשַׁעְנָא רַבָּא

Leap months

Detail of the Ishtar Gate of Babylon, dating from the era of the Babylonian captivity. The Ishtar Gate ( Assyrian: ܕܵܪܘܲܐܙܲܐ ܕܥܵܐܫܬܲܪ translit Darwaza D'Ishtar, Arabic:بوابة عشتار was the

Due to the difference in length between twelve lunar months and a solar year, a purely lunar calendar cycle would have resulted in the gradual shifting of the Hebrew calendar independently of the seasons. However, the Torah requires that certain festivals take place during certain seasons. A season is one of the major divisions of the Year, generally based on yearly periodic changes in Weather. This implies that a system of reconciling lunar months in the context of solar years and consequently seasons was in use. The Bible does not directly mention the addition of an "embolismic" or intercalary month that would prevent the drifting of the calendar year. Intercalation is the insertion of a leap day week or month into some calendar years to make the calendar follow the seasons or moon phases

Whether or not an embolismic month was announced after the "last month" (Adar) depended on whether "the barley was ripe". Adar ( Hebrew: אֲדָר, Standard Adar Tiberian ʾĂḏār; from Akkadian It may be noted that in the Bible the name of the first month, Aviv, literally means "spring" but originally it probably meant "the ripening of barley". This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer Thus, if Adar was over and the barley was not yet ripe, an additional month was observed. However, according to some traditions, the announcement of the month of Aviv could also be postponed depending on the condition of roads used by families to come to Jerusalem for Passover, adequate numbers of lambs to be sacrificed at the Temple, and on the ripeness of the barley that was needed for the first fruits ceremony. This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer Passover ( Hebrew, Yiddish: פֶּסַח Pesach, Tiberian: pɛsaħ Israeli: Pesah, Pesakh, Yiddish Barley ( Hordeum vulgare) is an annual Cereal Grain, which serves as a major animal Feed crop, with smaller amounts used for

Under the codified rules, the Jewish calendar is based on the Metonic cycle of 19 years, of which 12 are common years (12 months) and 7 leap years (13 months). Metonic cycle or Enneadecaeteris in Astronomy and Calendar studies is a particular approximate common multiple of the Tropical year The leap years are years 3, 6, 8, 11, 14, 17, and 19 of the Metonic cycle. Year 19 (there is no year 0) of the Metonic cycle is a year exactly divisible by 19 (when the Jewish year number, when divided by 19, has no remainder). In the same manner, the remainder of the division indicates the year in the Metonic cycle (years 1 to 18) the year is in.

During leap years a month, Adar II, is added before Nisan. Adar ( Hebrew: אֲדָר, Standard Adar Tiberian ʾĂḏār; from Akkadian During leap years Adar I (or Adar Aleph — "first Adar") is actually considered to be the extra month, and has 30 days. A leap year (or intercalary year) is a year containing one or more extra days (or in the case of Lunisolar calendars an extra month in order to keep the is the reconstructed name of the first letter of the Proto-Canaanite alphabet, continued in descended Semitic alphabets as Phoenician Adar II (or Adar Bet — "second Adar") is the "real" Adar, and has the usual 29 days. Bet, Beth, or Vet is the second letter of many Semitic abjads, including Phoenician For this reason, during a leap year, holidays such as Purim are observed in Adar II, not Adar I. Purim ( Hebrew: פורים Pûrîm " lots " related to Akkadian pūru) is a Jewish holiday that commemorates

New year

A shofar made from a ram's horn is traditionally blown in observance of Rosh Hashana, the beginning of the Jewish civic year. A shofar (שופר is a horn used for Jewish religious purposes Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish

The Jewish year has four distinct starting points, according to the Mishnah, Rosh Hashanah 1:1:

The day most commonly referred to as the "New Year" is the first of Tishrei, when the formal New Year festival, Rosh Hashanah ("head of the year") is observed. The Mishnah or Mishna (he משנה "repetition" from the verb shanah he שנה or "to study and review" is a major work of Rabbinic Judaism Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish (see Ezekiel 40:1, which uses the phrase "beginning of the year". ) This is the beginning of the civil year, and the point at which the year number advances. Certain agricultural practices are also marked from this date. ^[12]

However, the first month of the year as prescribed in Exodus 12:2 is Nisan: "This month shall be to you the beginning of months". This article is about the Jewish month of Nisan See Nissan Motors for the automobile manufacturer This means that the civil new year, Rosh Hashanah, actually begins in the seventh month of the year.

The month of Elul is the new year for counting animal tithes (ma'aser). Elul (אֱלוּל Standard Elul Tiberian ʾĔlûl; from Akkadian elūlu) is the twelfth The Maaser Rishon, meaning First Tithe in Hebrew (derived from the word eser, meaning tenth is the setting aside of one tenth of Income and Tu Bishvat ("the 15th of Shevat") marks the new year for trees (and agricultural tithes). Tu Bishvat (or Tu B'Shevat) ( ט״ו בשבט) is a minor Jewish holiday in the Hebrew month of Shevat usually sometime in late January or early February Shevat (or Shvat) ( Hebrew: שְׁבָט, Standard Šəvat Tiberian Šəḇāṭ

There may be an echo here of a controversy in the Talmud about whether the world was created in Tishrei or Nisan; it was decided that the answer is Tishrei, and this is now reflected in the prayers on Rosh Hashanah. The Talmud ( Hebrew: he תַּלְמוּד is a record of Rabbinic discussions pertaining to Jewish law, ethics, customs and history ^[13]

Epoch

The Jewish calendar uses a calendar era anno mundi ("in the year of the world"), abbreviated AM. A calendar era is the year numbering system used by a Calendar. la Anno Mundi (Latin "in the year of the World " abbreviated as AM or A Interestingly, the beginning of "year 1" is not Creation, but about one year before Creation. This caused the new moon of its first month (Tishrei) to be called molad tohu (the mean new moon of chaos or nothing).

The Jewish calendar's epoch (reference date), 1 Tishrei 1 anno mundi, is equivalent to Monday, October 7 3761 BCE in the proleptic Julian calendar, the equivalent tabular date (same daylight period) and is about one year before the traditional Jewish date of Creation on 25 Elul AM 1, based upon the Seder Olam Rabbah of Rabbi Yossi ben Halafta, a second century CE sage. In the fields of Chronology and Periodization, an epoch means an instant in time chosen as the origin of a particular Era. la Anno Mundi (Latin "in the year of the World " abbreviated as AM or A Events 3761 BC - The epoch (origin of the modern Hebrew calendar ( Proleptic Julian calendar) The proleptic Julian calendar is produced by extending the Julian calendar to dates preceding AD 4 when its quadrennial leap year stabilized Cultures throughout history have believed the world formed or was formed at some time in the past so methods of dating Creation have involved analysing scriptures and some physical Seder Olam Rabbah ( Hebrew: סדר עולם רבה) is the earliest post-exilic chronicle preserved in the Hebrew language. Rabbi Jose ben Halafta or Yose ben Halafta ( Hebrew: רבי יוסי בן חלפתא) was a Tanna of the fourth generation (2nd century CE ^[14] Thus, adding 3760 or 3761^[15] to any Julian/Gregorian year number after 1 CE will yield the Hebrew year. For earlier years there may be a discrepancy (see: "Missing Years" in the Hebrew Calendar).

Karaite interpretation

For several centuries, many Karaites, especially those outside Israel, followed the calculated Rabbinical calendar used by most Jews for the sake of convenience. Karaite Judaism or Karaism (ˈkærəˌaɪt ˈkærəˌɪzəm) is a Jewish movement NOTE The word sect should not be used without defining it first and However, in recent years most Karaites have chosen to again follow the observational method.

Karaites use the lunar month and the solar year, but the Karaite calendar differs from the Rabbinical calendar in two ways: the determination of the first day of each month (Rosh Chodesh), and the determination of the first month of the year (called aviv), which is the month in which Passover falls. Rosh Chodesh, (ראש חודש trans. Beginning of the Month; lit. Aviv ( Hebrew: אביב) has a few meanings in Hebrew: Aviv literally means spring; it is one of the four Seasons

For Karaites, the beginning of each month, the Rosh Chodesh, can be calculated, but is confirmed by the observation in Israel of the first sightings of the new moon. Rosh Chodesh, (ראש חודש trans. Beginning of the Month; lit. For a topic outline on this subject see List of basic Israel topics. This may result in an occasional variation of a maximum of one day, depending on the inability to observe the new moon. The day is usually "picked up" in the next month.

The addition of the leap month (Adar II) is determined by observing in Israel the ripening of barley (called abib), rather than using the calculated and fixed calendar of Rabbinic Judaism. Aviv ( Hebrew: אביב) has a few meanings in Hebrew: Aviv literally means spring; it is one of the four Seasons Rabbinic Judaism or Rabbinism ( Hebrew: " Yehadut Rabanit " - יהדות רבנית is the mainstream religious system of post- diaspora The four rules of postponement are not applied, as they are not found in the Tanakh. See also Old testament, Septuagint, Targum, Peshitta The Tanakh (תַּנַ"ךְ (taˈnax or; also Tenakh or Tenak is Occasionally this results in Karaites being one month ahead of Jews using the calculated Rabbinic calendar. The "lost" month would be "picked up" in the next cycle when Karaites would observe a leap month while other Jews would not.

Change to a calculated calendar

Observational principles

A stone (2. 43x1 m) with Hebrew inscription "To the Trumpeting Place" is believed to be a part of the Second Temple. The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International

Before the destruction of the Second Temple in 70 CE and the general disruption of Jewish communal life after the Jewish-Roman Wars, and for a transitional period thereafter, the new moons/months were determined on an observational basis. The Second Temple (בית המקדש romanized 'Beit HaMikdash' meaning 'Holy House' was the reconstructed Temple in Jerusalem which stood between 516 BCE and 70 CE

In Second Temple times (c. The Second Temple (בית המקדש romanized 'Beit HaMikdash' meaning 'Holy House' was the reconstructed Temple in Jerusalem which stood between 516 BCE and 70 CE 518 BCE – 70 CE), the beginning of each lunar month was decided on the basis of two eyewitnesses testifying to having seen the new lunar crescent at sunset. Patriarch Gamaliel II (c. Rabban Gamaliel II (also spelled Gamliel רבן גמליאל דיבנה was the first person to lead the Sanhedrin as Nasi after the fall of the second temple which 100) asked the witnesses to select the appearance of the moon from a collection of drawings that depicted the crescent in a variety of orientations, only a few of which could be valid in any given month. According to tradition, these observations were compared against calculations made by the supreme Jewish court, the Sanhedrin. The Sanhedrin (סנהדרין συνέδριον ''synedrion'', "sitting together" hence " assembly " or "council" was an assembly When thirty days elapsed since the last new moon, the witnesses were readily believed.

At first the beginning of each Jewish month was signaled to the communities of Israel and beyond by fires lit on mountaintops, but after the Samaritans and Boethusians began to light false fires, messengers were sent. The Boethusians were a Jewish sect closely related to if not a development of the Sadducees. The inability of the messengers to reach communities outside Israel before mid-month High Holy Days (Succot, Passover) led outlying communities to celebrate scriptural festivals for two days rather than one, observing the second feast-day of the Jewish diaspora because of uncertainty of whether the previous month ended after 29 or 30 days. Sukkot ( also known as Succoth, Sukkos, Feast of Booths or Feast of Tabernacles) is a Biblical Pilgrimage The Jewish diaspora ( Hebrew: Tefutzah, "scattered" or Galut גלות "exile" Yiddish: tfutses) the presence

1st–3rd centuries CE

In Rome the Arch of Titus still stands, depicting the enslaved Judeans and objects from the Temple being brought to Rome. The Arch of Titus is a Pentelic marble Triumphal arch with a single arched opening located on the Via Sacra just to the south-east of the Forum Titus Flavius Vespasianus, commonly known as Titus ( December 30 39 &ndash September 13 81) was a Roman Emperor who

By the Roman era some sects, such as the Essenes, used a solar calendar during the last two centuries BCE. The Essenes were strictly speaking a Jewish religious group that flourished from the 2nd century BC to the 1st century AD

The Jewish-Roman wars of 66–73, 115–117, and 132–135 caused major disruptions in Jewish life, also disrupting the calendar. During the third and fourth centuries, Christian sources describe the use of eight, nineteen, and 84 year lunisolar cycles by Jews, all linked to the civil calendars used by various communities of Diaspora Jews, which were effectively isolated from Levant Jews and their calendar. A Christian is a person who adheres to Christianity, a monotheistic Religion centered on the life and teachings of Jesus of Nazareth The term Diaspora (in Greek, διασπορά &ndash " a scattering or sowing of seeds " refers any population sharing common ethnic See also Names of the Levant The Levant (lə'vænt is a geographical term that denotes a large area in Western Asia, roughly bounded on the north by the Some assigned major Jewish festivals to fixed solar calendar dates, whereas others used epacts to specify how many days before major civil solar dates Jewish lunar months were to begin. The epact (from Greek epaktai hèmerai = added days is a quantification of the difference between the solar and lunar calendars

The Talmud notes the irregular intercalation (adding of extra months) performed in three successive years in the early second century.

The Ethiopic Christian computus (used to calculate Easter) describes in detail a Jewish calendar which must have been used by Alexandrian Jews near the end of the third century. NOTE This intro is the result of careful NPOV work Please do not make potentially controversial edits to it without first discussing on the talk page Computus ( Latin for Computation) is the Calculation of the date of Easter in the Christian calendar. Easter ( Greek: Πάσχα Pascha or Pasxa) is the most important religious feast in the Christian Liturgical year. Alexandria ( Egyptian Arabic: اسكندريه Eskendereyya; Standard Arabic: ar الإسكندرية Al-Iskandariyya; Ἀλεξάνδρεια ^[16] These Jews formed a relatively new community in the aftermath of the annihilation (by murder or enslavement) of all Alexandrian Jews by Emperor Trajan at the end of the 115–117 Kitos War. Marcus Ulpius Nerva Traianus, commonly known as Trajan ( September 18 53 &ndash August 9 117) was a Roman Emperor who The Kitos War ( 115 — 117) (מרד הגלויות mered ha'galoyot or mered ha'tfutzot (מרד התפוצות translation Rebellion of the Their calendar used the same epacts in nineteen year cycles that were to become canonical in the Easter computus used by almost all medieval Christians, both those in the Latin West and the Hellenist East. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. This article focuses on the cultural aspects of the Hellenistic age for the historical aspects see Hellenistic period. Only those churches beyond the eastern border of the Byzantine Empire differed, changing one epact every nineteen years, causing four Easters every 532 years to differ.

Transitional period

The period between 70 and 1178 saw a gradual transition from an observation based calendar to a purely mathematically calculated one. Except for the modern year number, the modern rules reached their final form before 820 or 921, with some uncertainty regarding when. The rules were codified in 1178 by Maimonides, who described all of the modern rules, including the modern epochal year. Moses Maimonides ( March 30 1135 – December 13 1204) also known as the Rambam, was a Rabbi, Physician, and

Under the patriarchate of Rabbi Judah III (300-330) the testimony of the witnesses with regard to the appearance of the new moon was received as a mere formality, the settlement of the day depending entirely on calculation. Originally a patriarch was a man who exercised autocratic authority as a Pater familias over an extended family Judah III ( Hebrew: יהודה נשיאה) held the office of Nasi of the ancient Jewish Sanhedrin between 290 and 320 CE This innovation seems to have been viewed with disfavor by some members of the Sanhedrin, particularly Rabbi Jose, who wrote to both the Babylonian and the Alexandrian communities, advising them to follow the customs of their fathers and continue to celebrate two days, an advice which was followed, and is still followed, by the majority of Jews living outside of Israel. The Sanhedrin (סנהדרין συνέδριον ''synedrion'', "sitting together" hence " assembly " or "council" was an assembly Rabbi Jose ben Halafta or Yose ben Halafta ( Hebrew: רבי יוסי בן חלפתא) was a Tanna of the fourth generation (2nd century CE

Traditionally, intercalations were determined at meetings of a special calendar commission of the Sanhedrin. The Sanhedrin (סנהדרין συνέδριον ''synedrion'', "sitting together" hence " assembly " or "council" was an assembly But Constantius II, following the precedents of Hadrian, prohibited the holding of such meetings. Flavius Iulius Constantius, known in English as Constantius II ( 7 August, 317 - November 3, 361) was a Roman Emperor Publius Aelius Hadrianus (January 24 76 &ndash July 10 138 as emperor Imperator Caesar Divi Traiani filius Traianus Hadrianus Augustus, and Divus Hadrianus after However, the Jewish community outside the land of Israel depended on the calendar sanctioned by the Judean Sanhedrin for the proper observance of the Jewish holidays. Judea or Judæa ( Hebrew: יהודה Standard Yəhuda Tiberian Yəhûḏāh, "praised The Sanhedrin (סנהדרין συνέδριον ''synedrion'', "sitting together" hence " assembly " or "council" was an assembly For the Gregorian dates of Jewish Holidays see Jewish holidays 2000-2050. However, danger threatened the participants in that sanction and the messengers who communicated their decisions to distant congregations. Temporarily, to relieve the foreign congregations, Huna ben Abin once advised Rava not to wait for the official intercalation:

When you are convinced that the winter quarter will extend beyond the sixteenth day of Nisan declare the year a leap year, and do not hesitate (R. H. 21a). Rava (רבא was a Jewish Talmudist who lived in Babylonia, known as an Amora, born in 270 and one of the most often-cited Rabbis in the Rosh Hashanah (ראש השנה is the name of a text of Jewish law originating in the Mishnah which formed the basis of tractates in both the Babylonian Talmud

There is a popular tradition, first mentioned by Hai Gaon (d. Hai ben Sherira, better known as Hai Gaon, was a medieval Jewish theologian Rabbi and scholar who served as Gaon of the Talmudic academy 1038), that as religious persecutions continued, Patriarch Hillel II determined to provide an authorized mathematically-based calendar for all time to come, though by so doing he severed the ties which united the Jews of the diaspora to their mother country and to the patriarchate. Hillel II, ( Hebrew: הלל נשיאה Hillel the Nasi) also known simply as Hillel held the office of Nasi of the ancient Jewish The Jewish diaspora ( Hebrew: Tefutzah, "scattered" or Galut גלות "exile" Yiddish: tfutses) the presence Palestine is a name which has been widely used since Roman times to refer to the region between the Mediterranean Sea and the Jordan River. A patriarchate is the Office or jurisdiction of a Patriarch. A patriarch as the term is used here is either one of the highest-ranking It is recorded that the calendar was adopted at a clandestine, and maybe final, meeting of the Sanhedrin in 358, marking the last universal decision made by that body.

This explanation has been questioned. It is noted that the Talmud, which did not reach its final form until c. 500, does not mention the continuous calendar or even anything as mundane as either the nineteen-year cycle or the length of any month, despite discussing the characteristics of earlier calendars, suggesting the final form of the modern calendar was fixed subsequent to the sixth century.

Furthermore, Jewish dates during post-Talmudic times (specifically in 506 and 776) are impossible using modern rules, and all evidence points to the development of the arithmetic rules of the modern calendar in Babylonia during the times of the Geonim (seventh to eighth centuries), under the Abbasid Caliphate. Geonim ( Hebrew: גאונים also transliterated Gaonim) were the presidents of the two great rabbinical colleges of Sura The Caliph is the Head of state in a Caliphate, and the title for the leader of the Islamic Ummah, an Islamic community ruled by the Shari'ah The Babylonian rules required the delay of the first day of Tishrei when the new moon occurred after noon. This article is about the lunar phase for other uses see New Moon (disambiguation. Noon (also midday) is the hour of 1200 in an observer's local time zone or more loosely a time near the middle of the day when workers in many countries take a meal break

Most of the modern rules appear to have been in place by about 820, according to a treatise by the Muslim astronomer Muḥammad ibn Mūsā al-Ḵwārizmī (c. A Muslim (مسلم pronounced Muslim, not Muzlim) is an adherent of the Religion 780-850 CE) a Persian polymath noted for his contributions to Islamic mathematics, Islamic astronomy, Islamic astrology and geography. layout and formatting it should ensure no clashes with the top of the infobox A polymath ( Greek polymathēs, πολυμαθής "having learned much" is a person whose knowledge is not restricted to one subject area This is a sub-article of History of science in the Islamic World and Astrology. Geography (from Greek γεωγραφία - geografia) is the study of the Earth and its lands features inhabitants and phenomena Al-Khwārizmī's study of the Jewish calendar, Risāla fi istikhrāj taʾrīkh al-yahūd "Extraction of the Jewish Era" describes the 19-year intercalation cycle, the rules for determining on what day of the week the first day of the month Tishrī shall fall, the interval between the Jewish era (creation of Adam) and the Seleucid era, and the rules for determining the mean longitude of the sun and the moon using the Jewish calendar. Metonic cycle or Enneadecaeteris in Astronomy and Calendar studies is a particular approximate common multiple of the Tropical year Tishrei (or Tishri) (ˈtɪʃri or) ( Hebrew: תִּשְׁרֵי‎ ( תִּשְׁרִי‎) Standard Tišre la Anno Mundi (Latin "in the year of the World " abbreviated as AM or A The Seleucid era was a system of numbering Years in use by the Seleucid Empire and other countries among the ancient Hellenistic civilizations The era

One notable difference between the calendar of that era and the modern form was the date of the epoch (the fixed reference point at the beginning of year 1), which at that time was one year later than the epoch of the modern calendar. In the fields of Chronology and Periodization, an epoch means an instant in time chosen as the origin of a particular Era.

In 921 Aaron ben Meir, a leader of the Jewish community in Palestine otherwise unknown to history, sought to return the authority for the calendar to the Land of Israel by asserting that the first day of Tishrei should be the day of the new moon unless the new moon occurred more than 642 parts (35⅔ minutes, where a "part" is ¹/₁₀₈₀ of an hour or ¹/₁₈ of a minute or 3⅓ seconds) after noon, when it should be delayed by one or two days. Aaron ben Meïr was a Palestinian Nasi (head of the Sanhedrin in the first half of the Tenth century. Palestine is a name which has been widely used since Roman times to refer to the region between the Mediterranean Sea and the Jordan River. For other uses see Israel (disambiguation The Land of Israel ( Hebrew: אֶרֶץ יִשְׂרָאֵל Eretz Yisrael) is He may have been asserting that the calendar should be run according to Jerusalem time, not Babylonian. Local time on the Babylonian meridian was indeed about 642 parts (35 minutes and 40 seconds) later than (ahead of) the meridian of Jerusalem, corresponding to a longitude difference of 8° 55'. This article is about the geographical concept For other uses of the word see Meridian. Jerusalem (יְרוּשָׁלַיִם, he-Latn Yerushaláyim; Arabic: ar القُدس, ar-Latn al-Quds) is the

An alternative explanation for the 642 parts is that Ben Meir may have believed, along with many earlier Jewish scholars, in a Creation theology placing Creation in the Spring season, and that the calendar rules had been adjusted by 642 parts to fit in with an Autumn date. If Creation occurred in the Autumn, to coincide with the observance of Rosh Hashana, the calculated time of New Moon during the six days of creation was on Friday at 14 hours exactly (counting from the day starting at 6pm the previous evening). Autumn (also known as fall in North American English) is one of the four Temperate Seasons Autumn marks the transition from Summer Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish However, if Creation actually occurred six months earlier, in the Spring, the new moon would have occurred at 9 hours and 642 parts on Wednesday. Spring is one of the four Temperate Seasons Spring marks the transition from Winter into Summer.

In any event, he was opposed by Saadiah Gaon of the Talmudic academy of Sura. Sura (sometimes spelt "Surah" ar سورة, plural "Suwar" ar سور is an Arabic term literally meaning "something enclosed or surrounded Only a few Jewish communities accepted ben Meir's opinion, and even these soon rejected it. Accounts of the controversy show that all of the rules of the modern calendar (except for the epoch) were in place before 921.

Codification of rules

In 1000 the Muslim chronologist al-Biruni also described all of the modern rules, except that he specified three different epochs used by various Jewish communities being one, two, or three years later than the modern epoch. Finally, in 1178 Maimonides described all of the modern rules, including the modern epochal year. Moses Maimonides ( March 30 1135 – December 13 1204) also known as the Rambam, was a Rabbi, Physician, and

In his work Mishneh Torah of 1178, Maimonides included a chapter "Sanctification of the New Moon," in which he discusses the calendrical rules and their scriptural basis. The Mishneh Torah ( Hebrew: משנה תורה subtitled Sefer Yad ha-Chazaka (יד החזקה is a code of Jewish Religious law He notes,

"By how much does the solar year exceed the lunar year? By approximately 11 days. Therefore, whenever this excess accumulates to about 30 days, or a little more or less, one month is added and the particular year is made to consist of 13 months, and this is the so-called embolismic (intercalated) year. For the year could not consist of twelve months plus so-and-so many days, since it is said: throughout the months of the year (Num. 28:14), which implies that we should count the year by months and not by days. "^[10]

Maimonides continues, showing analytically how the scriptural procedure for determining the calendar must be flawed, something he could explain through his faith. He noted that non-Jewish savants had presented mathematically correct methods of calculating the potential visibility of the new crescent, and reasoned that since these methods exist, they must have been used by the Court and the record of their use lost. ^[17]

If one back-calculates the moments of the traditional moladot using modern astronomical calculations then the closest that their reference meridian of longitude ever got to Israel was midway between the Nile River and the end of the Euphrates River (about 4° east of Jerusalem), and that was in the era of the Second Temple. Longitude (ˈlɒndʒɪˌtjuːd or ˈlɒŋgɪˌtjuːd symbolized by the Greek character Lambda (λ is the east-west Geographic coordinate measurement The Nile (النيل, Ancient Egyptian iteru or Ḥ'pī, Coptic piaro or phiaro) is a major north-flowing River The Euphrates ( ( Arabic: ar نهر الفرات; Turkish: tr Fırat Syriac: syr ܦܪܬ; Hebrew: he פרת

From the times of the Amoraim (third to fifth centuries), calculations were increasingly used, for example by Samuel the astronomer, who stated during the first half of the third century that the year contained 365 ¼ days, and by "calculators of the calendar" circa 300. Samuel of Nehardea or Samuel bar Abba ( Hebrew: שמואל) was a Jewish Talmudist who lived in Babylonia, known as an Jose, an Amora who lived during the second half of the fourth century, stated that the feast of Purim, 14 Adar, could not fall on a Sabbath nor a Monday, lest 10 Tishrei (Yom Kippur) fall on a Friday or a Sunday. Purim ( Hebrew: פורים Pûrîm " lots " related to Akkadian pūru) is a Jewish holiday that commemorates Yom Kippur (יוֹם כִּפּוּר ˈjɔm kiˈpur also known in English as the Day of Atonement, is the most solemn and important of the Jewish holidays Its This indicates a fixed number of days in all months from Adar to Elul, also implying that the extra month was already a second Adar added before the regular Adar.

Epoch

The Jewish calendar's reference point is traditionally held to be about one year before the Creation of the world.

The Jewish calendar uses a calendar era anno mundi ("in the year of the world"), abbreviated AM. A calendar era is the year numbering system used by a Calendar. la Anno Mundi (Latin "in the year of the World " abbreviated as AM or A Interestingly, the beginning of "year 1" is not Creation, but about one year before Creation. This caused the new moon of its first month (Tishrei) to be called molad tohu (the mean new moon of chaos or nothing).

Its epoch (reference date), 1 Tishrei 1 AM, is equivalent to Monday, October 7 3761 BCE in the proleptic Julian calendar, the equivalent tabular date (same daylight period). In the fields of Chronology and Periodization, an epoch means an instant in time chosen as the origin of a particular Era. Events 3761 BC - The epoch (origin of the modern Hebrew calendar ( Proleptic Julian calendar) The proleptic Julian calendar is produced by extending the Julian calendar to dates preceding AD 4 when its quadrennial leap year stabilized This date is about one year before the traditional Jewish date of Creation on 25 Elul AM 1, based upon the Seder Olam of Rabbi Yossi ben Halafta, a second century CE sage. Cultures throughout history have believed the world formed or was formed at some time in the past so methods of dating Creation have involved analysing scriptures and some physical Rabbi Jose ben Halafta or Yose ben Halafta ( Hebrew: רבי יוסי בן חלפתא) was a Tanna of the fourth generation (2nd century CE (A minority opinion places Creation on 25 Adar AM 1, six months earlier, or six months after the modern epoch. ) Thus, adding 3760 (from September-October through December 3761) to any Julian/Gregorian year number after 1 CE will yield the Jewish year, ending in September-October, which roughly coincides with that Julian/Gregorian year. Owing to the slow drift of the modern Jewish calendar relative to the Gregorian calendar, this will be true for about another 20,000 years.

The traditional Jewish date for the destruction of the First Temple (3338 AM = 423 BCE) differs from the modern scientific date, which is usually expressed using the Gregorian calendar (586 BCE). Solomon's Temple (בית המקדש transliterated Beit HaMikdash) also known as the First Temple, was according to The scientific date takes into account evidence from the ancient Babylonian calendar and its astronomical observations. In this and related cases, a difference between the traditional Jewish year and a scientific date in a Gregorian year results from a disagreement about when the event happened — and not simply a difference between the Jewish and Gregorian calendars. See the "Missing Years" in the Jewish Calendar.

Principles

Measurement of month

Animation of the Moon as it cycles through its phases, as seen from the Northern Hemisphere. The apparent wobbling of the Moon is known as libration. In Astronomy libration (from the Latin verb librare "to balance to sway" cf

Synodic month

A synodic month (known in Hebrew as a "molad") is a scientifically defined lunar conjunction based on the position of the moon in the lunar orbit. The month is a unit of Time, used with Calendars which is approximately as long as some natural period related to the motion of the Moon; Molad (plural Moladot) is a Hebrew word meaning "birth" that also generically refers to the time at which the New Moon is "born" A lunar conjunction is the event when the earth moon and sun in that order are approximately in a straight line In Astronomy, lunar orbit (also known as a Selenocentric orbit) refers to the orbit of an object around the Moon. It equals exactly ⁷⁶⁵⁴³³/₂₅₉₂₀ days, or 29 days, 12 hours, and 793 parts (44+¹/₁₈ minutes) (ie 29. 5306 days). This interval matches the mean synodic month determined by the Babylonians before 300 BCE and as adopted by the Greek astronomer Hipparchus and the Alexandrian astronomer Ptolemy. Hipparchus ( Greek; ca 190 BC &ndash ca 120 BC was a Greek Astronomer, Geographer, and Mathematician of the Hellenistic Claudius Ptolemaeus ( Greek: Klaúdios Ptolemaîos; after 83 &ndash ca Its remarkable accuracy is thought to have been achieved using records of lunar eclipses from the eighth to fifth centuries BCE, with a reference meridian midway between the Nile River and the end of the Euphrates River, about 4° east of Jerusalem.

Traditional new moon

A "new moon" is the day on which the first visible crescent of the moon is observed. This article is about the lunar phase for other uses see New Moon (disambiguation. It occurs 29 or 30 days after the preceding visible crescent and traditionally signaled the start of a Jewish lunar month.

Combining the observation method with the scientific lunar month length works as follows. Assume one begins at a particular new month of 29 days. As the mean lunar month is 29. 5306 days long, there would be a carry forward into the next month of 0. 5306 days (ie 12 hours, 44+¹/₁₈ minutes). Adding that carry forward amount to the next month will make it equal 30. 0612 days (30 days, 1 hour and 24+²/₁₈ minutes). So the second month would be 30 days long, and 0. 0612 days (or 1 hour 24+²/₁₈ minutes) would be carried forward to be added to the next cycle, and so on. Then every 17 lunar months the carry forward amounts would exceed 24 hours (0. 0612 x 17 = 1. 0404), which would require an additional day to be added to that month. In summary, the progression becomes: year 1 | 29 – 30 – 29 – 30 – 29 – 30 – 29 – 30 – 29 – 30 – 29 – 30 | year 2 | 29 – 30 – 29 – 30 – 30 – 29 – etc.

Pattern of calendar years

The Jewish calendar is based on the Metonic cycle of 19 years, of which 12 are common years (12 months) and 7 leap years (13 months). A Metonic cycle equates to 235 lunar months in each 19-year cycle. This gives an average of 6939 days, 16 hours and 595 parts for each cycle.

But due to the Rosh HaShanah postponement rules (see below), a cycle of 19 Jewish years can be either 6939, 6940, 6941, or 6942 days in duration. Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish Since none of these values is evenly divisible by seven, the Jewish calendar repeats exactly only following 36,288 Metonic cycles, or 689,472 Jewish years. There is a near-repetition every 247 years, except for an excess of 50 minutes (905 parts).

There are 14 different patterns that Jewish years may take. Each of these patterns is called a "keviyah" (Hebrew for "a setting" or "an established thing"), and is distinguished by the day of the week for Rosh Hashanah of that particular year and by that particular year's length.

A Jewish non-leap year can only have 353, 354, or 355 days. A leap year can have 383, 384, or 385 days (always 30 days longer than the non-leap length).

• A chaserah year (Hebrew for "deficient" or "incomplete") is 353 or 383 days long. Both Kislev and Cheshvan have 29 days. The Hebrew letter ח "het", and the letter for the weekday denotes this pattern.
• A kesidrah year ("regular" or "in-order") is 354 or 384 days long. Kislev has 29 days and Cheshvan has 30 days. The Hebrew letter כ "kaf", and the letter for the week-day denotes this pattern.
• A shlemah year ("abundant" or "complete") is 355 or 385 days long. Both Kislev and Cheshvan have 30 days. The Hebrew letter ש "shin", and the letter for the week-day denotes this pattern.

Determining leap years

The Jewish leap years are years 3, 6, 8, 11, 14, 17, and 19 of the Metonic cycle. To determine whether a year is a leap year, find the remainder when dividing the Jewish year number by 19. In Arithmetic, when the result of the division of two Integers cannot be expressed with an integer Quotient, the remainder is the amount "left If the remainder is 3, 6, 8, 11, 14 or 17, the year is a leap year and an extra month, Adar II, is added. If the remainder is zero, the year is also a leap year since year 19 of the Metonic cycle is a year exactly divisible by 19. Another way to check a specific year is to find the remainder in the following calculation: ( 7 x the Jewish year number + 1 ) / 19. If the remainder is less than 7, the year is a leap year.

A mnemonic word in Hebrew is GUCHADZaT "גוחאדז"ט" (the Hebrew letters gimel-vav-het aleph-dalet-zayin-tet, i. e. 3, 6, 8, 1, 4, 7, 9. See Hebrew numerals). The system of Hebrew numerals is a quasi-decimal alphabetic Numeral system using the letters of the Hebrew alphabet. A variant of this pattern of naming includes another letter which specifies the day of the week for the first day of Pesach (Passover) in the year.

Another memory aid notes that intervals of the major scale follow the same pattern as do Jewish leap years, with do corresponding to year 19 (or 0): a whole step in the scale corresponds to two common years between consecutive leap years, and a half step to one common year between two leap years. In Music theory, the major scale or Ionian scale is one of the diatonic scales It is made up of seven distinct Notes plus an eighth A major second () also called a whole step or a whole tone, is a Musical interval that occurs between the first and second degrees of a A semitone, also called a half step or a half tone, is the smallest Musical interval commonly used in Western tonal music and it is considered the

Special holiday rules

Adjustments are needed to ensure certain holy days and festivals do or do not fall on certain days of the week in the coming year.

Rosh Hashanah postponement rules

Although simple math would calculate 21 patterns for calendar years, there are other limitations which mean that Rosh Hashanah may only occur on Mondays, Tuesdays, Thursdays, and Saturdays (the "four gates"), according to the table. Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish

That means that the pattern can be varied to ensure that Rosh Hashanah does not fall on the other 3 days. This is to ensure that Yom Kippur does not directly precede or follow Shabbat, which would create practical difficulties, and that Hoshana Rabbah is not on a Shabbat, in which case certain ceremonies would be lost for a year. Yom Kippur (יוֹם כִּפּוּר ˈjɔm kiˈpur also known in English as the Day of Atonement, is the most solemn and important of the Jewish holidays Its Shabbat or Shabbos ( Hebrew: שַׁבָּת, shabbāt, shabbes, "rest/inactivity" is the Weekly Sabbath The seventh day of the Jewish holiday of Sukkot, 21st day of Tishrei, is known as Hoshana Rabbah ( Aramaic: הוֹשַׁעְנָא רַבָּא

Yom Kippur

Yom Kippur, on which no work can be done, can never fall on Friday (the day prior to the Sabbath), to avoid having the previous day's fast day still going on at the start of Sabbath. Shabbat or Shabbos ( Hebrew: שַׁבָּת, shabbāt, shabbes, "rest/inactivity" is the Weekly Sabbath Thus some flexibility has been built in.

Leap years

In leap years, a 30 day month called Adar I is inserted immediately after the month of Shevat, and the regular 29 day month of Adar is called Adar II. This is done to ensure that the months of the Jewish calendar always fall in roughly the same seasons of the solar year, and in particular that Nisan is always in spring. Whether either Chesvan or Kislev both have 29 days, or both have 30 days, or one has 29 days and the other 30 days depends upon the number of days needed in each year. Thus a leap year of 13 months has an average length of 383½ days, so for this reason alone sometimes a leap year needs 383 and sometimes 384 days.

The 265 days from the first day of the 29 day month of Adar (i. e. the twelfth month, but the thirteenth month, Adar II, in leap years) and ending with the 29th day of Heshvan forms a fixed length period that has all of the festivals specified in the Bible, such as Pesach (Nisan 15), Shavuot (Sivan 6), Rosh Hashana (Tishrei 1), Yom Kippur (Tishrei 10), Sukkot (Tishrei 15), and Shemini Atzeret (Tishrei 22). Passover ( Hebrew, Yiddish: פֶּסַח Pesach, Tiberian: pɛsaħ Israeli: Pesah, Pesakh, Yiddish Shavuot (or Shavuos, in Ashkenazi usage Hebrew: שבועות, lit Rosh Hashanah (ראש השנה literally "head of the year" Biblical: ˈɾoʃ haʃːɔˈnɔh Israeli haʃaˈna Yiddish: hɑˈʃɔnə is a Jewish Yom Kippur (יוֹם כִּפּוּר ˈjɔm kiˈpur also known in English as the Day of Atonement, is the most solemn and important of the Jewish holidays Its Sukkot ( also known as Succoth, Sukkos, Feast of Booths or Feast of Tabernacles) is a Biblical Pilgrimage Shemini Atzeret (שמיני עצרת - "the Eighth of Assembly" is a Jewish holiday celebrated on the 22nd day of the Hebrew month of Tishrei.

Pesach

The festival period from Pesach up to and including Shemini Atzeret is exactly 185 days long. Passover ( Hebrew, Yiddish: פֶּסַח Pesach, Tiberian: pɛsaħ Israeli: Pesah, Pesakh, Yiddish Shemini Atzeret (שמיני עצרת - "the Eighth of Assembly" is a Jewish holiday celebrated on the 22nd day of the Hebrew month of Tishrei. The time from the traditional day of the vernal equinox up to and including the traditional day of the autumnal equinox is also exactly 185 days long. An equinox is the event of the Sun passing over the Earth's equator in its annual cycle This has caused some unfounded speculation that Pesach should be March 21 and Shemini Atzeret should be September 21, which are the traditional days for the equinoxes. Just as the Hebrew day starts at sunset, the Hebrew year starts in the Autumn (Rosh Hashanah), although the mismatch of solar and lunar years will eventually move it to another season if the modern fixed calendar isn't moved back to its original form of being judged by the Sanhedrin (which requires the Beit Hamikdash)

Measurement of hours

Every hour is divided into 1080 halakim or parts. Etymology The Hebrew name given in Scripture for the building is Beit HaMikdash or "The Holy House" and only the Temple in Jerusalem is referred to by this name A part is 3⅓ seconds or ¹/₁₈ minute. The ultimate ancestor of the helek was a small Babylonian time period called a barleycorn, itself equal to ¹/₇₂ of a Babylonian time degree (1° of celestial rotation). Actually, the barleycorn or she was the name applied to the smallest units of all Babylonian measurements, whether of length, area, volume, weight, angle, or time.

But by the twelfth century that source had been forgotten, causing Maimonides to speculate that there were 1080 parts in an hour because that number was evenly divisible by all numbers from 1 to 10 except 7. Moses Maimonides ( March 30 1135 – December 13 1204) also known as the Rambam, was a Rabbi, Physician, and But the same statement can be made regarding 360. The weekdays start with Sunday (day 1) and proceed to Saturday (day 7). Since some calculations use division, a remainder of 0 signifies Saturday.

While calculations of days, months and years are based on fixed hours equal to ¹/₂₄ of a day, the beginning of each halachic day is based on the local time of sunset. Sunset, also called sundown in some American English Dialects is the instant when the trailing edge of the Sun 's disk disappears below The end of the Shabbat and other Jewish holidays is based on nightfall (Tzeis Hacochavim) which occurs some amount of time, typically 42 to 72 minutes, after sunset. For the Gregorian dates of Jewish Holidays see Jewish holidays 2000-2050. According to Maimonides, nightfall occurs when three medium-sized stars become visible after sunset. By the seventeenth century this had become three second-magnitude stars. The modern definition is when the center of the sun is 7° below the geometric (airless) horizon, somewhat later than civil twilight at 6°. The beginning of the daytime portion of each day is determined both by dawn and sunrise. Dawn refers to the Twilight before Sunrise. It is recognized by the presence of weak sunlight while the sun itself is still below the horizon Sunrise is the instant at which the upper edge of the Sun appears above the Horizon in the East. Most halachic times are based on some combination of these four times and vary from day to day throughout the year and also vary significantly depending on location. The daytime hours are often divided into Shaos Zemaniyos or "Halachic hours" by taking the time between sunrise and sunset or between dawn and nightfall and dividing it into 12 equal hours. The earliest and latest times for Jewish services, the latest time to eat Chametz on the day before Passover and many other rules are based on Shaos Zemaniyos. Jewish services ( Hebrew: תפלה, tefillah; plural תפלות, tefillos or tefillot; Yinglish: davening Chametz (חָמֵץ (also Chometz or Chumetz) refers to bread grains and leavened products that are not consumed on the Jewish holiday of Passover Passover ( Hebrew, Yiddish: פֶּסַח Pesach, Tiberian: pɛsaħ Israeli: Pesah, Pesakh, Yiddish For convenience, the day using Shaos Zemaniyos is often discussed as if sunset were at 6:00pm, sunrise at 6:00am and each hour were equal to a fixed hour. For example, halachic noon may be after 1:00pm in some areas during daylight saving time. Noon (also midday) is the hour of 1200 in an observer's local time zone or more loosely a time near the middle of the day when workers in many countries take a meal break Daylight saving time ( DST

Accuracy

Irregularities and "Missing Years"

Main article: Missing Years

The traditional dates of events in Jewish history are often used interchangeably with the modern secular dates according to the Gregorian calendar. The Gregorian calendar is the most widely used Calendar in the world today For example, year 3338 AM on the Hebrew calendar is typically equated to 586 BCE. Implicit in this practice is the view that if all the differences in structure between the Hebrew and Gregorian calendars are taken into consideration, the two dates can be derived from each other. This is not the case. If the traditional dates of events before the Second Temple era are assumed to be using the standard Hebrew calendar, they refer to different objective years than those of the secular dates. The discrepancy is some 165 years.

The conflict does not necessarily imply that either the traditional dates or the secular dates must be objectively wrong. It is possible that the traditional dates did not use a consistent calendar matching the year count of the standard Hebrew calendar. It could be that one or more substantial calendar shifts have occurred, or the years counted might in certain periods have differed from astronomical years. Taking into account the possibility of a changing structure of the Hebrew calendar, theoretically, both the traditional dates and those of secular scholars could be correct. Even so, the account of history in the traditional sourcebook Seder Olam Rabba, and in particular its description of the period of Persian domination, seems to be irrevocably at odds with modern scientific understanding. Seder Olam Rabbah ( Hebrew: סדר עולם רבה) is the earliest post-exilic chronicle preserved in the Hebrew language.

Furthermore, the modern Hebrew calendar cannot be used to calculate Biblical dates because new moon dates may be in error by ±2 days and months may be in error by ±2 months. Etymology According to the Online Etymology Dictionary, the word bible is from Latin biblia, traced from the same word through Medieval Latin and Late Latin The latter accounts for the irregular intercalation (adding of extra months) that was performed in three successive years in the early second century, according to the Talmud. The Talmud ( Hebrew: he תַּלְמוּד is a record of Rabbinic discussions pertaining to Jewish law, ethics, customs and history

Mean year length

The Hebrew calendar mean year is 365. 2468 days long, or 365 days, 5 hours 55 minutes, and 25+²⁵/₅₇ seconds (the molad/monthly interval × 235 months per 19-year cycle ÷ 19 years per cycle). As the present-era mean northward equinoctial year is about 365 days 5 hours 49 minutes and zero seconds long, the Hebrew calendar mean year is about 6 minutes and 25+²⁵/₅₇ seconds longer than the modern fixed solar year. This amounts to approximately one day in every 224 years.

In addition, since the mean Gregorian calendar year is 365. The Gregorian calendar is the most widely used Calendar in the world today 2425 days (exactly 365 days 5 hours 49 minutes and 12 seconds) and the mean Hebrew calendar year is 365. 2468 days, the Hebrew calendar falls behind the Gregorian calendar by about a day every 231 years.

Molad intervals

The source of the discrepancy is the difference between the molad interval and the actual lunar conjunction cycle. The molad interval is currently about 0. 6 seconds too long, and the discrepancy is accumulating at an accelerating rate, since the mean lunation interval is progressively shortening due to gravitational tidal effects. Characteristics A tide is a repeated cycle of sea level changes in the following stages Over several hours the water rises or advances up a beach in the flood The accumulated "error" since the era of Hillel II is such that the molad moments are now almost 1 hour and 40 minutes late relative to the mean lunar conjunctions at the original reference meridian, which was midway between the Nile River and the end of the Euphrates River. The Nile (النيل, Ancient Egyptian iteru or Ḥ'pī, Coptic piaro or phiaro) is a major north-flowing River The Euphrates ( ( Arabic: ar نهر الفرات; Turkish: tr Fırat Syriac: syr ܦܪܬ; Hebrew: he פרת The modern molad moments match the mean solar times of the lunar conjunction moments near the meridian of Kandahar, Afghanistan, more than 30° east of Jerusalem. For the 2001 film see Kandahar (film; for the Kandahar meteorite of 1959 see Meteorite falls; for the places in Azerbaijan see Cəndəhar and Afghanistan /æfˈgænɪstæn/ officially the Islamic Republic of Afghanistan ( Pashto: د افغانستان اسلامي جمهوریت, Longitude (ˈlɒndʒɪˌtjuːd or ˈlɒŋgɪˌtjuːd symbolized by the Greek character Lambda (λ is the east-west Geographic coordinate measurement

In the present era actual lunar conjunction intervals can be as short as 29 days 6 hours and 30 minutes to as long as 29 days and 20 hours, an astonishing variation range of about 13 hours and 30 minutes. Furthermore, due to the eccentricity of Earth's orbit, series of shorter lunations alternate with series of longer lunations, consequently the actual lunar conjunction moments can range from 12 hours earlier than to 16 hours later than the molad moment, in terms of Jerusalem mean solar time (make the conjunction moments 16 minutes earlier if referred to the original molad reference meridian midway between the Nile River and the end of the Euphrates River, about 4° east of Jerusalem). Today, in terms of the mean solar time at the meridian of Qandahar, Afghanistan the actual lunar conjunctions vary ±14 hours relative to the traditional moladot.

Measured on a strictly uniform time scale, such as that provided by an atomic clock, the mean synodic month is becoming gradually longer, but since due to the tides the Earth rotation rate slowing even more the mean synodic month is becoming gradually shorter in terms of mean solar time. An atomic clock is a type of Clock that uses an Atomic resonance Frequency standard as its timekeeping element The value 29-12-793 was almost exactly correct at the time of Hillel II and is now about 0. Hillel II, ( Hebrew: הלל נשיאה Hillel the Nasi) also known simply as Hillel held the office of Nasi of the ancient Jewish 6 seconds per month too long. However, it is still the most correct value possible as long as only whole parts (¹/₁₈ minute) are used.

Implications for Jewish ritual

This figure, in a detail of a medieval Hebrew calendar, reminded Jews of the palm branch (Lulav), the myrtle twigs, the willow branches, and the citron (Etrog) to be held in the hand and to be brought to the synagogue during the holiday of sukkot, near the end of the autumn holiday season. Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering Lulav (לולב is a ripe green closed frond of the Date palm tree The citron is a fragrant fruit with the botanical name Citrus medica L Sukkot ( also known as Succoth, Sukkos, Feast of Booths or Feast of Tabernacles) is a Biblical Pilgrimage

Although the molad of Tishrei is the only molad moment that is not ritually announced, it is actually the only one that is relevant to the Hebrew calendar, for it determines the provisional date of Rosh HaShanah, subject to the Rosh HaShanah postponement rules. The other monthly molad moments are announced for mystical reasons. With the moladot on average almost 100 minutes late, this means that the molad of Tishrei lands one day later than it ought to in (100 minutes) ÷ (1440 minutes per day) = 5 of 72 years or nearly 7% of years!

Therefore the seemingly small drift of the moladot is already significant enough to affect the date of Rosh HaShanah, which then cascades to many other dates in the calendar year and sometimes, due to the Rosh HaShanah postponement rules, also interacts with the dates of the prior or next year. The molad drift could be corrected by using a progressively shorter molad interval that corresponds to the actual mean lunar conjunction interval at the original molad reference meridian. Furthermore, the molad interval determines the calendar mean year, so using a progressively shorter molad interval would help correct the excessive length of the Hebrew calendar mean year, as well as helping it to "hold onto" the northward equinox for the maximum duration.

If the intention of the calendar is that Passover should fall near the first full moon after the northward equinox, or that the northward equinox should land within one lunation before 16 days after the molad of Nisan, then this is still the case in about 80% of years, but in about 20% of years Passover is a month late by these criteria (as it was in Hebrew year 5765, an 8th year of the 19-year cycle = Gregorian 2005 AD). Presently this occurs after the "premature" insertion of a leap month in years 8, 19, and 11 of each 19-year cycle, which causes the northward equinox to land at exceptionally early moments in such years. This problem will get worse over time, and so beginning in Hebrew year 5817 the 3rd year of each 19-year cycle will also be a month late. Furthermore, the drift will accelerate in the future as perihelion approaches and then passes the northward equinox, and if the calendar is not amended then Passover will start to land on or after the summer solstice around Hebrew year 16652, or about 10885 years from the present. (The exact year when this will begin to occur depends on uncertainties in the future tidal slowing of the Earth rotation rate, and on the accuracy of predictions of precession and Earth axial tilt. )

The seriousness of the spring equinox drift is widely discounted on the grounds that Passover will remain in the spring season for many millennia, and the text of the Torah is generally not interpreted as having specified tight calendrical limits. On the other hand, the mean southward equinoctial year length is considerably shorter, so the Hebrew calendar has been drifting faster with respect to the autumn equinox, and at least part of the harvest festival of Sukkot is already more than a month after the equinox in years 9, 1, 12 and 4 of each 19-year cycle (these are the same year numbers as were mentioned for the spring season in the previous paragraph, except that they get incremented at Rosh HaShanah). This progressively increases the probability that Sukkot will be cold and wet, making it uncomfortable or impractical to dwell in the traditional succah during Sukkot. The first winter seasonal prayer for rain is not recited until Shemini Atzeret, after the end of Sukkot, yet it is becoming increasingly likely that the rainy season in Israel will start before the end of Sukkot.

"Rectifying" the Hebrew calendar

Given the importance in Jewish ritual of establishing the accurate timing of monthly and annual times, some futurist writers and researchers have considered whether a "corrected" system of establishing the Hebrew date is required, due to the small but accelerating changes in the actual lunar cycle interval. Futurists, or futurologists, are those who speculate about the future Further religious questions include how such a system might be implemented and administered throughout the diverse aspects of the world Jewish community.

It is traditionally held that the fixed arithmetic Hebrew calendar was established on the authority of Hillel ben Yehudah, President of the Sanhedrin in Hebrew year 4119, and therefore only an equal authority (the modern Sanhedrin) or a higher authority (the Messiah) can either amend it or reinstate the observational Hebrew calendar. Messiah ( משיח; mashiah, moshiah, mashiach, or moshiach, ("anointed " is a term used in the Hebrew Bible

A 353-year leap cycle of 4366 months, including 130 leap months, along with use of a progressively shorter molad interval, could keep an amended fixed arithmetic Hebrew calendar from drifting for more than 7 millennia. ^[18]

Usage in contemporary Israel

Early Zionist pioneers were impressed by the fact that the calendar preserved by Jews over many centuries in far flung diasporas, as a matter of religious ritual, was geared to the climate of their original country: the Jewish New Year marks the moment of transition from the Dry Season to the Rainy one, and major Jewish Holidays such as Sukkot, Passover or Shavuot correspond to major points of the country's agricultural year such as planting and harvest. History of Zionism|Timeline of Zionism|World Zionist Organization|Zionist political violence Zionism is an international political movement that originally supported the Shavuot (or Shavuos, in Ashkenazi usage Hebrew: שבועות, lit

Accordingly, in the early 20th Century the Hebrew Calendar was re-interpreted as an agricultural rather than religious calendar. The Kibbutz movement was especially inventive in creating new rituals fitting this interpretation. A kibbutz ( Hebrew: קיבוץ קִבּוּץ lit "gathering clustering" plural kibbutzim) is a collective community in

With the creation of the State of Israel the Hebrew Calendar was made its official calendar. For a topic outline on this subject see List of basic Israel topics. New holidays and commemorations not derived from previous Jewish tradition invariably were to be defined according to their Hebrew dates — notably the Israeli Independence Day on Iyar 5, Jerusalem Reunification Day on 28 Iyar, and the Holocaust Commemoration Day on Nisan 27 (close to the Hebrew date of the start of the Warsaw Ghetto Uprising). The Warsaw Ghetto Uprising (German "Aufstand im Warschauer Ghetto", Polish "Powstanie w getcie warszawskim") was the Jewish

Nevertheless, since the 1950s the Hebrew calendar steadily declined in importance in Israeli daily life, in favor of the worldwide Gregorian Calendar. The Gregorian calendar is the most widely used Calendar in the world today At present, Israelis — except for the minority of religiously observant — conduct their private and public life according to the Gregorian Calendar.

The Jewish New Year (Rosh Hashana) is a two-day public holiday in Israel. However, since the 1980s an increasing number of secularist Israelis had taken up the habit of celebrating the Gregorian New Year (usually known as "Sylvester Night" — "ליל סילבסטר") by holding all-night parties on the night between December 31 and January 1. Prominent Rabbis have on several occasions sharply denounced this practice, but with no noticeable effect on the secularist celebrants.

The disparity between the two calendars is especially noticeable with regard to commemoration of the assassinated Prime Minister Yitzchak Rabin. The official Day of Commemoration, instituted by a special Knesset law, is marked according to the Hebrew Calendar - on Heshvan 12. For Beit Knesset a Jewish Place of worship, see Synagogue. The Knesset (כנסת lit However, left-leaning Israelis, who revere Rabin as a martyr for the cause of peace and who are predominantly secularist, prefer to hold their own mass memorial rallies on November 4. In some years the two competing Rabin Memorial Days are separated by as much as two weeks.

The wall calendars commonly used in Israel are hybrids — organised according to Gregorian rather than Jewish months, but beginning in September, where the Jewish New Year usually falls, and providing the Jewish date in small characters.

Notes

This article incorporates text from the 1901–1906 Jewish Encyclopedia, a publication now in the public domain. The Jewish Encyclopedia was an Encyclopedia originally published between 1901 and 1906 by Funk and Wagnalls. The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone

References

• The Code of Maimonides (Mishneh Torah), Book Three, Treatise Eight: Sanctification of the New Moon. Translated by Solomon Gandz. Yale Judaica Series Volume XI, Yale University Press, New Haven, Conn. , 1956.
• Ernest Wiesenberg. "Appendix: Addenda and Corrigenda to Treatise VIII". The Code of Maimonides (Mishneh Torah), Book Three: The Book of Seasons. Yale Judaica Series Volume XIV, Yale University Press, New Haven, Conn. , 1961. pp. 557-602.
• Samuel Poznanski. Samuel Abraham Poznański or Shemuel Avraham Poznanski ( Lubraniec, 3 September 1864 –­1921 was a Polish Reform rabbi and scholar known for "Calendar (Jewish)". Encylopædia of Religion and Ethics, 1911.
• al-Biruni. The Chronology of Ancient Nations, Chapter VII. tr. C. Edward Sachau. London, 1879.
• F. H. Woods. "Calendar (Hebrew)", Encylopædia of Religion and Ethics, 1911.
• Sherrard Beaumont Burnaby. Elements of the Jewish and Muhammadan Calendars. George Bell and Sons, London, 1901.
• W. H. Feldman. Rabbinical Mathematics and Astronomy,3rd edition, Sepher-Hermon Press, 1978.
• Otto Neugebauer. Ethiopic astronomy and computus. Österreichische Akademie der Wissenschaften, philosophisch-historische klasse, sitzungsberichte 347. Vienna, 1979.
• Ari Belenkiy. "A Unique Feature of the Jewish Calendar — Dehiyot". Culture and Cosmos 6 (2002) 3-22.
• Arthur Spier. The Comprehensive Hebrew Calendar. Feldheim, 1986.
• Nathan Bushwick. Understanding the Jewish Calendar. Moznaim, 1989. ISBN 0940118173
• L. A. Resnikoff. "Jewish calendar calculations", Scripta Mathematica 9 (1943) 191-195, 274-277. Scripta Mathematica was a quarterly journal published by Yeshiva University devoted to the philosophy history and expository treatment of mathematics
• Edward M. Reingold and Nachum Dershowitz. Edward M Reingold is a Computer scientist active in the fields of Algorithms Data structures and Calendrical calculations He has co-authored the Calendrical Calculations: The Millennium Edition. Cambridge University Press; 2 edition (2001). ISBN 0-521-77752-6
• Bonnie Blackburn and Leofranc Holford-Strevens. The Oxford Companion to the Year: An Exploration of Calendar Customs and Time-reckoning. Oxford University Press; USA, 2000. pp 723-730.

See also

• Babylonian calendar
• Jewish holidays 2000-2050
• molad

External links

• Ancient Jewish Text calculates Lunar Month
• Perpetual Hebrew / Civil Calendar
• Jewish Calendar Details various Jewish points-of-view about the history of the Jewish calendar/Hebrew calendar. The Babylonian calendar was a Lunisolar calendar with years consisting of 12 Lunar months each beginning when a new crescent moon was first sighted low Molad (plural Moladot) is a Hebrew word meaning "birth" that also generically refers to the time at which the New Moon is "born" Includes several charts.
• Hebrew Calendar Science and Myth gives complete rules of the Hebrew calendar and a lot more.
• The Jewish Controversy about Calendar Postponements
• Jewish Calendar with Zmanim - Halachic times and date converter chabad. org
• Jewish calendar scientific explanation at the NASA web site
• Jewish Encyclopedia: Calendar
• Calendar Hebrew for Christians website
• Karaite Holidays Karaite website
• Hebrew CalendarDates and Holydays (Diaspora or Israel)
• The Lengths of the Seasons (numerical integration analysis)
• The Hebrew Calendar (astronomical analyses)
• The Molad of the Hebrew Calendar (astronomical analysis)
• The Rectified Hebrew Calendar (calendar reform proposal, includes full arithmetic algorithms for both the Traditional and the Rectified calendars)
• Hebrew - Gregorian Calendar with options (Multilingual)
• Bet Ha Bracha Hebrew Calendar

Date converters

• Jewish Calendar for Outlook - Incorporate Jewish dates and holidays into Microsoft Office Outlook. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Karaite Judaism or Karaism (ˈkærəˌaɪt ˈkærəˌɪzəm) is a Jewish movement NOTE The word sect should not be used without defining it first and Microsoft Outlook or Outlook (full name Microsoft Office Outlook since Outlook 2003 is a Personal information manager from Microsoft, and is
• Molad - Jewish Calendar with Zmanim and holidays for Mobiles.
• Kaluach - Hebrew/civil calendars
• Hebcal Hebrew Date Converter
• Jewish/Gregorian/Julian Perpetual Calendar Converter - Also contains a full year view for the Hebrew Calendar.
• Sample VB.Net and Javascript code to convert the Hebrew Date to the Gregorian Date
• Jewish / Civil Date Converter
• Software program that converts Hebrew dates to the civil calendar and vice versa
• Gregorian-Mayan-Julian-Islamic-Persian-Hebrew Calendar Converter
• Kalendis Calendar Calculator
• Gregorian to Hebrew date with weekly Parshat HaShavua.
• Full Jewish Year in Hebrew Characters
• Full Jewish Year in Western Characters