The Jewish Calendar

Updated February 21, 2017 | Factmonster Staff

The Jewish calendar is based on both solar and lunar years. The average lunar year of about 354 days is adjusted to the solar year by the addition of a leap year and an intercalary month. Nisan is considered the first month, although the new year begins with Rosh Hashanah, on the first of Tishri, which is in fact the seventh month—the calendar has different starting points for different purposes. The year 2008 translates to the Jewish year 5768–5769. The year 2009 translates to the Jewish year 5769–5770.

Month Number
of days
Nisan (March–April)* 30
Iyar (April–May) 29
Sivan (May–June) 30
Tammuz (June–July) 29
Av (July–Aug.) 30
Elul (Aug.–Sept.) 29
Tishri (Sept.–Oct.) 30
Heshvan (Oct.–Nov.) 29
 in some years 30
Kislev (Nov.–Dec.) 29
 in some years 30
Tevet (Dec.–Jan.) 29
Shevat (Jan.–Feb.) 30
Adar (Feb.–March) 29
 in some years 30
Adar Sheni 29
 (intercalary month
 in leap year only)
*The months correspond approximately to those of the Gregorian calendar.

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