#22 Jewish Time – Days/Months/Years

#22 Jewish Time – Days/Months/Years

The Hebrew calendar follows a seven-day weekly cycle, which runs concurrently with but independently of the monthly and annual cycles. As you learned in Lesson #21 Jewish Lunisolar Calendar, the Jewish calendar is based on a combination of Sun and Moon rotations with a leap year every 7 years.

#1 WATCH: Jewish Days of the Week – names

#2 STUDY: Days of the Week

  1. Yom Rishon – יום ראשון (abbreviated יום א׳), meaning “first day” [corresponds to Sunday] (starting at preceding sunset of Saturday)
  2. Yom Sheni – יום שני (abbr. יום ב׳) meaning “second day” [corresponds to Monday]
  3. Yom Shlishi – יום שלישי (abbr. יום ג׳) meaning “third day” [corresponds to Tuesday]
  4. Yom Reviʻi – יום רביעי (abbr. יום ד׳) meaning “fourth day” [corresponds to Wednesday]
  5. Yom Chamishi – יום חמישי (abbr. יום ה׳) = “fifth day” [corresponds to Thursday]
  6. Yom Shishi – יום ששי (abbr. יום ו׳) meaning “sixth day” [corresponds to Friday]
  7. Yom Shabbat – יום שבת (abbr. יום ש׳), or more usually Shabbat – שבת = “Sabbath-rest day” [corresponds to Saturday]. Also known as Yom Shabbat Kodesh יום שבת קודש

#3 WATCH: 12 or 13 Months in the Jewish Calendar? Or both?

#4 STUDY: The Jewish Months

The Hebrew calendar is a lunisolar calendar, meaning that months are based on lunar months, but years are based on solar years. The calendar year features twelve lunar months of twenty-nine or thirty days, with a leap lunar month added periodically to synchronize the twelve lunar cycles with the longer solar year. (These extra months are added seven times every nineteen years.  The beginning of each Jewish lunar month is based on the appearance of the new moon. Although originally the new lunar crescent had to be observed and certified by witnesses,the moment of the true new moon is now approximated arithmetically.

The lunar month is very close to 29.5 days. Accordingly, the basic Hebrew calendar year is one of twelve lunar months alternating between 29 and 30 days:

No. Hebrew months Length
1 Nisan 30
2 Iyar 29
3 Sivan 30
4 Tammuz 29
5 Av 30
6 Elul 29
7 Tishrei 30
8 Marcheshvan
(or Cheshvan)
9 Kislev 30/29
10 Tevet 29
11 Shevat 30
12 Adar 29
Total 353, 354 or 355

In leap years (such as 5774) an additional month, Adar I (30 days) is added after Shevat, while the regular Adar is referred to as “Adar II.”

The insertion of the leap month mentioned above is based on the requirement that Passover—the festival celebrating the Exodus from Egypt, which took place in the Spring—always occurs in the [northern hemisphere’s] spring season. Since the adoption of a fixed calendar, intercalations in the Hebrew calendar have been assigned to fixed points in a 19-year cycle. Prior to this, the intercalation was determined empirically:

The year may be intercalated on three grounds: ‘aviv [i.e.the ripeness of barley], fruits of trees, and the equinox. On two of these grounds it should be intercalated, but not on one of them alone.[14]


#5 Text Study

The day most commonly referred to as the “New Year” is Rosh Hashanah (1 Tishrei), which actually begins in the seventh month of the ecclesiastical year. On that day the formal New Year for the counting of years is observed. This is the civil new year, and the date on which the year number advances. Certain agricultural practices are also marked from this date.[37]

In the 1st century, Josephus stated that while –

Moses…appointed Nisan…as the first month for the festivals…the commencement of the year for everything relating to divine worship, but for selling and buying and other ordinary affairs he preserved the ancient order [i. e. the year beginning with Tishrei.









# 6 Review and Response

1. What is the method used to name the days of the Jewish week?
2. Is the Hebrew Calendar based on Solar, Lunar, or Lunisolar?
3. How many days are in the regular Jewish calendar year?
4. What month is added during the Jewish leap year?
5. What is the first day of the year in the Jewish calendar?

Need some help? We’re here for you. At any time, if you have any questions, please contact one of our teachers so we can help you. Also, at the end of the session, remember to review your responses in your Tamid Workbook so you can get credit for this lesson. Behatzlacha (Hebrew for good luck)! You can reach Sarah at (646)360-0689 or connect@tamidnyc.org