Hebrew calendar converter
Convert any Gregorian date to the Hebrew (Jewish) calendar. The tool shows the day, the Hebrew month, and the Anno Mundi (AM) year — the count from the traditional date of creation. It is useful for finding yahrzeit (memorial) dates, festival dates, and the Hebrew date on a birth or wedding certificate.
How it works
The converter uses the fixed, arithmetic (molad-based) Hebrew calendar — the same rules in universal civil and religious use, independent of any astronomical observation. It converts your Gregorian date to a Julian Day Number (a continuous count of days), then maps that number onto the Hebrew calendar by determining the AM year, applying the four postponement rules (dehiyyot) that fix when Rosh Hashanah may fall, and counting forward through the months. In a leap year (7 of every 19), the month of Adar splits into Adar I and Adar II. Because the Hebrew day begins at sunset, a civil date near nightfall may map to the following Hebrew day.
The Hebrew months at a glance
| Hebrew month | Approx. Gregorian season | Notable occasion |
|---|---|---|
| Tishrei | Sep–Oct | Rosh Hashanah, Yom Kippur, Sukkot |
| Cheshvan | Oct–Nov | — |
| Kislev | Nov–Dec | Hanukkah begins |
| Tevet | Dec–Jan | — |
| Shevat | Jan–Feb | Tu BiShevat |
| Adar (/ Adar II in leap year) | Feb–Mar | Purim |
| Nisan | Mar–Apr | Passover (Pesach) |
| Iyyar | Apr–May | Lag BaOmer |
| Sivan | May–Jun | Shavuot |
| Tammuz | Jun–Jul | — |
| Av | Jul–Aug | Tisha B’Av |
| Elul | Aug–Sep | Month of repentance |
Months alternate between 29 and 30 days, with Cheshvan and Kislev varying between years to make the calendar obey the postponement rules.
Understanding Anno Mundi (AM)
The year 2026 CE straddles AM 5786 and AM 5787 — the Hebrew year number changes at Rosh Hashanah in the autumn. From Rosh Hashanah 5786 (October 2025) to Rosh Hashanah 5787 (September 2026), every Gregorian date in that window belongs to AM 5786. After Rosh Hashanah 5787, the year becomes 5787 for dates through the following autumn.
This is why, for example, a birth in January 2026 will show a lower AM year than a birth in November 2026 even though they share the same Gregorian year.
Common uses
Yahrzeit: A yahrzeit (anniversary of death) is observed on the Hebrew date of passing, not the civil date. If a relative died on a certain civil date, converting to the Hebrew date gives the correct observance date each year going forward. Note that yahrzeit shifts slightly on the civil calendar each year, since the Hebrew year is lunisolar.
Festival planning: Jewish holidays are fixed to the Hebrew calendar, so knowing the Hebrew date for an upcoming civil date is the quickest way to check whether a day coincides with a festival.
Historical research: Older Jewish community records (marriage registers, gravestones, memorial books) often record dates in the Hebrew calendar. Converting back to Gregorian helps correlate them with civil records.
Example
The Gregorian date 15 April 2026 converts to roughly 28 Nisan 5786 (AM). The year is 5786 because Rosh Hashanah 5786 fell in autumn 2025, and Nisan is the spring month in which Passover falls.
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