Hebrew Calendar
Converter
Convert between Gregorian and Hebrew (Jewish) dates
Gregorian date
Hebrew date
Hebcal reference dates
- 8 July 2026 — 23 Tamuz 5786
- 1 Tishrei 5787 (Rosh Hashana) — 12 September 2026
- 25 Kislev 5787 — 5 December 2026
Dates use the standard Hebrew calendar rules as implemented by Hebcal (@hebcal/core). Jewish holidays that begin at sundown may be observed on the preceding Gregorian evening.
How it works
The Hebrew calendar is a lunisolar calendar: months follow the lunar cycle (29 or 30 days), while leap years add an extra month so the calendar stays roughly aligned with the solar year and the seasons. Unlike the purely lunar Islamic (Hijri) calendar, which drifts about 11 days earlier each Gregorian year, the Hebrew calendar uses a 19-year leap cycle to keep festivals such as Passover in their seasonal place.
A Hebrew year begins in Tishrei (around September or October) and may have 12 or 13 months. In leap years, Adar is split into Adar I and Adar II. Month lengths vary — Cheshvan and Kislev can be 29 or 30 days depending on the year — which makes hand-rolled conversion error-prone.
Clockr uses the Hebcal library (@hebcal/core), the same engine behind hebcal.com, for authoritative Gregorian ↔ Hebrew conversion. Enter a date on either side and the other updates automatically. For holidays that start at sundown, the civil Gregorian date shown here is the calendar day on which that Hebrew date falls during daylight hours.
Frequently asked questions
Why does the Hebrew calendar have a leap month?
Passover must fall in the spring, which requires the calendar to track the solar year, not just the Moon. Roughly every three years, a leap month (Adar II) is inserted in the 19-year Metonic cycle so that lunar months do not drift out of season. This is different from the Hijri calendar, which has no leap month and therefore shifts through all seasons over a 33-year cycle.
Is this conversion exact?
Yes, for the standard rabbinic Hebrew calendar rules implemented by Hebcal. Given a Gregorian civil date, the corresponding Hebrew date is mathematically determined, and converting back recovers the original date exactly. The only nuance is holidays observed from sundown: a Hebrew date that begins Friday evening may be associated with Friday on the calendar even though observance starts Thursday night.
What is the difference between AM and CE years?
AM (Anno Mundi, "in the year of the world") counts years from the traditional Hebrew date of creation. CE (Common Era) is the Gregorian year count used internationally. The two systems use different starting points and month structures, so you cannot convert years by simple subtraction — but any single civil day maps to one Hebrew date and vice versa.
Why do some years have Adar I and Adar II?
In a leap year, the regular month of Adar becomes Adar I and an extra Adar II is added before Nisan. Purim is celebrated in Adar II during leap years. The month dropdown on this page shows Adar I and Adar II only when the selected Hebrew year is a leap year.
How does this differ from the Hijri calendar?
Both calendars are rooted in lunar months, but the Hebrew calendar adds intercalary months to stay aligned with the solar year, while the Hijri calendar does not. That is why Ramadan moves through all seasons over time, whereas Passover consistently falls in spring. Use our Hijri Calendar Converter for Islamic dates.