What is the Hebrew calendar?

The Hebrew calendar (also called the Jewish calendar) is a lunisolar calendar used by Jews worldwide for religious observances. It combines lunar months with solar years through a 19-year Metonic cycle, inserting a 13th month (Adar I) in 7 out of every 19 years to keep the calendar aligned with the seasons.

Hebrew months

The Hebrew year begins with Tishrei (the civil new year, Rosh Hashanah) and contains 12 months in a regular year and 13 months in a leap year:

Nisan, Iyar, Sivan, Tammuz, Av, Elul (spring/summer)
Tishrei, Cheshvan, Kislev, Tevet, Shevat, Adar (autumn/winter)
In leap years: Adar I (29 days) precedes Adar II (29 days)

The Hebrew year count (Anno Mundi)

The Hebrew calendar counts years from the traditional biblical date of creation, often given as 3761 BCE. The Hebrew year 5784 corresponds approximately to 2023–2024 CE. The Hebrew year count is called Anno Mundi (AM), Latin for "Year of the World".

The Metonic cycle

The Hebrew calendar uses a 19-year Metonic cycle (named after the Greek astronomer Meton of Athens) to keep lunar months aligned with solar years. Within each 19-year cycle, 12 years are regular (12 months each) and 7 years are leap years (13 months each), occurring in years 3, 6, 8, 11, 14, 17, and 19 of the cycle. This keeps the Hebrew calendar in sync with the solar year to within 2 hours over 19 years.

Jewish holidays and Gregorian drift

Since Hebrew calendar dates are fixed, their corresponding Gregorian dates shift approximately 11 days earlier each year (the difference between a 354-day lunar year and the 365-day solar year), correcting roughly every 3 years via a leap month. As a result, holidays fall in a window rather than on a fixed Gregorian date:

Rosh Hashanah: 1 Tishrei - falls September–October
Yom Kippur: 10 Tishrei - 9 days after Rosh Hashanah
Passover (Pesach): 15 Nisan - always in spring (March–April)
Hanukkah: 25 Kislev - falls November–December

Frequently asked questions

What Hebrew year is it now?

As of 2025 CE, the Hebrew year is 5785 (until Rosh Hashanah 2025, which begins year 5786).

Why do Hebrew dates shift relative to Gregorian dates?

Because the Hebrew calendar is lunisolar, months follow the moon but years track the sun. This means the same Hebrew date (e.g., 1 Nisan) falls on different Gregorian dates each year, shifting within a roughly 30-day range.

What is a Hebrew leap year?

A Hebrew leap year has 13 months instead of 12; the extra month is Adar I (29 days), inserted before the regular Adar (which becomes Adar II in leap years). Leap years occur in years 3, 6, 8, 11, 14, 17, and 19 of the 19-year Metonic cycle.