Calendar, Jewish

Jewish Calendar: derived from a Babylonian model, the Jewish calendar combines lunar months and solar years, and is still in use.

The Jewish year consists of twelve months of each 29 or 30 days. A regular year, therefore, has 354 days and is about 11 days shorter than the solar year. Therefore, eight extra ("intercalary") months are added in a nineteen-year cycle. The system was adopted from the Babylonian calendar.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
   
X
   
X
 
X
   
X
   
X
   
X
 
X
The Gezer Calendar

(The years with an X are years with a second Adar, and had, therefore, 383 days.) This calendar was c.360 CE introduced by patriarch Hillel II. In earlier centuries, intercalation was probably irregular, but it is not likely that this caused great discrepancies between the official and the solar calendar. After all, there were many religious festivals that were related to natural phenomena (e.g., the offering of the firstfruits of barley on 16 Nisan), and the authorities responsible for the intercalation had to keep the festivals in mind.

The sect at Qumran had another calendar that was designed to make sure that Passover would never be on a Sabbath. A similar measure can be found in the table below, in which the months of Marheshvan and Kislev can have either 29 or 30 days, an adjustment that is needed to prevent that Yom Kippur and the seventh day of Sukkot intervene with the Sabbath.

The Jews have two ways of counting their months. In the sacred calendar, Nisan is the first month (column 1); in the civil calendar, New Year is celebrated on the first day of Tishri (column 2). The third column gives the names of the months and the number of days; the fourth column mentions their equivalent in the western calendar. Column five gives the names of the most important religious festivals. The last column mentions the natural phenomena.

In the first centuries of the common era, the Jews discerned five seasons: harvest, hot season, seed time, winter and cold season.

1
2
Month
Julian calendar
Festivals
Natural phenomena
1
7
Nisan
30 days
March/April 14. Passover (Pesah)
16. Firstfruits of barley
Fall of the latter spring rains
Barley ripe; planting sesame
2
8
Iyyar
29 days
April/May 14. Second Passover (Pesah Sheni)
18. Lag BaOmer (commemoration of the end of second-century plague)
Harvest of barley, peas, lentils
Wheat ripens
3
9
Sivan
30 days
May/June 6. Feast of Weeks (Shawu'ot)
Firstfruits of wheat
Harvest of wheat
Begin of the summer (no rain until September)
4
10
Tammuz
29 days
June/July   Heat increases
Harvest chickpeas, first harvest of figs
5
11
Ab
30 days
July/August 9. Commemoration of the Fall of the Temple The streams dry up
Intense heat
6
12
Elul
29 days
August/September   Vintage of pomegranates and grapes;
second harvest of figs
7
1
Tishri
30 days
September/October 1. New Year (Rosh Hashanah)
10. Day of Atonement (Yom Kippur)
15-23. Feast of Tabernacles (Sukkot)
Firstfruits of wine and oil
Early rains
Processing of grapes
Plowing and sowing begins
Olives
8
2
Marheshvan
29/30 days
October/November   Continuous rain
Wheat, barley, and oats sown
Vintage in Galilee
9
3
Kislev
30/29 days
November/December 25. Feast of Dedication (Hanukah) Begin of winter. Snow on the mountains
Sowing peas, lentils, chicken peas, flax
10
4
Tebeth
29 days
December/January   Coldest month;
hail, snow.
11
5
Shebat
30 days
January/February 15. New Year of Trees Weather becomes warmer
Care for garden vegetables
12
6
Adar
29 days
February/March 14. Feast of Purim (Megillah) Thunder and hail frequent
Almond trees blossom; planting millet

Thanks...

... to Mr Leonard S. Berkowitz

This page was created in 1996; last modified on 23 September 2020.