The Hebrew or Jewish calendar is a lunar based calendar. It is used by many today primarily for the observance of Jewish religious holidays, feasts, fasts and festivals. The calendar sets the dates for Jewish holidays and ties the appropriate readings of the Law, the Psalms and the study of extra-biblical material like the Talmud/Torah.

To better understand the Jewish calendar and calculation of time involves three specific astrological events. The first is the rotation of the Earth on its axis – a day. Based on the description in Genesis of the beginning of creation, “an evening and a morning” prompts the believer to measure the day from sunset to sunset. The second event is the revolution of the moon around the Earth – a month. Finally time is seen with regard to the revolution of the Earth around the sun – a year.

The moon revolves around the Earth in about 29½ days, known as a lunar month. The Earth revolves around the sun in about 365¼ days, or about 12.4 lunar months. The Gregorian (civil) calendar that is currently used by most of the world has abandoned any correlation to the lunar calendar, setting months at lengths of 29, 30 or 31 days in an almost completely arbitrary fashion. Jewish months are either 29 or 30 days in length. Periodically, a 13th month is added to the year in order to balance the calculations.

The Jewish year represents the number of years since creation. The number is determined by adding up the ages of the people listed in Biblical genealogies dating back to Adam. This does not mean, however that all Jews hold to a young Earth view of time. Many traditional and Orthodox Jews will acknowledge that the first six “days” of creation are not necessarily 24-hour days.

Generally, people of the Jewish faith do not use the designations “A.D.” (the year of our Lord) and “B.C.” (before Christ). Instead the preferred acronym is C.E. (Common or Christian Era) and B.C.E. (Before Common Era). These terms are gaining acceptance among the secular and scientific world as well.

The first month of the Jewish calendar is in the spring, when Passover occurs. The Jewish New Year, however, is celebrated in Tishri, the seventh month. While it may seem strange to have a year start at a time different that January first, the beginning of “years” fluctuates for many. The school year tends to begin in August or September. Many businesses start their fiscal year in the summer.

Below is a chart which shows the Jewish Calendar months and the coinciding Secular (Gregorian) date ranges along with the notable Jewish Holiday for that month.

MONTH NUMBER

JEWISH

MONTH

SECULAR DATES

NUMBER OF DAYS

SPECIAL DATES

1

Nissan

March – April

30

Passover

2

Iyar

April – May

29

Lag B’Omer

3

Sivan

May – June

30

Shavuot

4

Tammuz

June – July

29

 

5

Av

July – August

30

Tish’ah B’Av

6

Elul

August – September

29

 

7

Tishri

September – October

30

High Holdiays (Rosh Hashanah and Yom Kippur) Sukkot, Shmini Atzeret, and Simchat Torah

8

Cheshvan

October – November

29 or 30

 

9

Kislev

November – December

30 or 29

Hanukkah

10

Tevet

December – January

29

 

11

Shevat

January – February

30

Tu B’Shvat

12

Adar I (leap years only)

February – March

30

 

13 (or 12)

Adar (called Adar Beit in leap years)

February – March

29

Purim