The Jewish Calendar
The Jewish Calendar is a combined solar/lunar calendar, in that it strives to have its years coincide with the tropical year and its months coincide with the synodic months. This is a complicated goal, and the rules of the Jewish calendar are correspondingly fascinating. It is based on the lunar year of 354 or 355 day per year. Seven times in 19 years the ad an additional month (leap year). The names of the months of the Jewish calendar were adopted during the time of Erza, after Israel returned from the Babylonian exile of 70 years. The names are actually Babylonian month names, brought back to Israel by the returning exiles. Note that most of the Bible refers to the months by number, not by name.
|Number||Month||Pronunciation||Days in Month||Corresponding Months of Gregorian calendar||Feasts and Events||11||Nisan||ne-san||30||March-April|| 14th Passover
15th Unleaven Bread
21st First Fruits
|2||Iyyar||e-yar||29||April-May||3||Sivan||sev-in||29||May-June||16th-17th Pentecost. Feast of Weeks, seven weeks after Passover||4||Tammauz||tam-mux||29||June-July||5||Av||aah-b||29||July-August||The Temple was destroyed on 9th of Av 70 AD||6||Elul||el-ool||29||August-September||7||Trihri2||tish-ri||30||September-October|| 1st Jewish New Year- Rosh Hashanna
Feast of Trumpets
10th Day of Atonement (Yom Kippur)
15th Feast of Tabernacles (Kukkoth)
|8||Cheshvan||ches-von||29-30||October-November||9||Kislev||kis-lov||30-29||November-December||10||Tevet||te-bet||29||December-January||Feast of Lights - Hannukkah which celebrates the redication of the Temple in 168 BC.||11||Shevat||sha-va</td>||29-30||January-February||12||Adar||are-dar||29-30||February-March||13-14th Purim (Celebrates Queen Esther and Mordecai saving the Jewish people from being destroyed during the Babylonian captivity||13||Adar II||are-dar||29||Intercalary3 Month (Leap Year)|
NOTES:- In leap years, Adar has 30 days. In non-leap years, Adar has 29 days.
- The length of Cheshvan and Kislev are determined by complex calculations involving the time of day of the full moon of the following year's Tishri and the day of the week that Tishri would occur in the following year.4
- Note that the number of days between Nisan and Tishri is always the same. Because of this, the time from the first major festival (Passover in Nissan) to the last major festival (Sukkot [sue-ka] in Tishri) is always the same.
- The date of Jewish holidays does not change from year to year. Holidays are celebrated on the same day of the Jewish calendar every year, but the Jewish year is not the same length as a solar year on the Gregorian calendar used by most of the western world, so the date shifts on the Gregorian calendar.
- The problem with strictly lunar calendars is that there are approximately 12.4 lunar months in every solar year, so a 12-month lunar calendar loses about 11 days every year and a 13-month lunar gains about 19 days every year. The months on such a calendar "drift" relative to the solar year. On a 12 month calendar, the month ofNissan, which is supposed to occur in the Spring, occurs 11 days earlier each year, eventually occurring in the Winter, the Fall, the Summer, and then the Spring again. To compensate for this drift, an extra month was occasionally added: a second month of Adar. The month ofNissan would occur 11 days earlier for two or three years, and then would jump forward 29 or 30 days, balancing out the drift.
- In the fourth century, Hillel IT established a fixed calendar based on mathematical and astronomical calculations. This calendar, still in use, standardized the length of months and the addition of months over the course of a 19 year cycle, so that the lunar calendar realigns with the solar years. Adar IT is added in the 3rd, 6th, 8th, 11th, 14th, 17th and 19th years of the cycle. The current cycle began in Jewish year 5758 (the year that began October 2, 1997).
In addition, Yom Kippur (Day of Atonemen) should not fall adjacent to Shabbat, (SabbathSaturday) because this would cause difficulties in coordinating the fast with Shabbat, and Hoshanah Rabba (New Years Day -First day of the year) should not fall on Saturday because it would interfere with the holiday's observances. A day is added to the month of Cheshvan or subtracted from the month Kislev of the previous year to these things from happening.
The days Jewish calendar year:5
- The first day of the calendar year, Rosh Hashanah, on 1 Tishri is determined as follows:
1The numbers of the month represent the ecclesiastical or religious calendar. For example Nisan is the first month of the ecceslteiastical year. It is the eight month of the civil year which begins Trishri 1.
2Trishri is the first month of the civil year.
3"Intercalary" means: something inserted.
4 Judaism 101
5 Calendars through the Ages