Hebrew Date Converter
Convert a Gregorian date to the Hebrew (Jewish) calendar and back, with the weekday and whether the Hebrew year is a leap year.
Result
Hebrew date: 23 Tishri 5787 AM
A Hebrew date begins at nightfall the evening before. Festivals outside Israel may add a second day; the page converts dates and does not list observances.
- Day of the week
- Sunday
- Hebrew year
- 5787 is a leap year of 13 months and 385 days (complete)
https://calcgallery.com/date-time/hebrew-date-converter-calculator/
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How to use the Hebrew Date Converter
- Choose whether you are converting a Gregorian date to Hebrew or a Hebrew date to Gregorian.
- For a Gregorian date, pick it in the date box. For a Hebrew date, enter the year (for example 5787), pick the month and enter the day.
- Read the converted date, its weekday and the length of that Hebrew year.
- If you pick Adar II in a year that has only one Adar, or a day the month does not have, the page tells you instead of guessing.
A calendar fixed by rule
Since the fourth century the Hebrew calendar has been worked out by fixed arithmetic rather than by watching for the new moon. Maimonides set out the rules in the twelfth century, and they are the ones this page follows. Nothing depends on where you are, and every date from 1583 to 2999 comes out the same as in any printed Jewish calendar.
mean lunation 29 days 12 hours 793 parts (1 part = 1/1080 hour)leap years 7 in every 19: (7 × year + 1) mod 19 < 7Rosh Hashanah mean new moon of Tishri, postponed by the four dehiyyotyear lengths 353–355 days, or 383–385 in a leap yearHow a date is converted
The page finds the day Rosh Hashanah falls on for the Hebrew year, then adds the lengths of the months before the one you chose. Heshvan and Kislev are the only months whose length changes, so that the year comes out to the length the postponements require. To go the other way, the page counts days from the Gregorian date to the nearest Rosh Hashanah and walks forward month by month.
The months are listed in the order the year runs, from Tishri, which is how calendars print them. The numbering of years starts in Tishri as well, so the year number changes at Rosh Hashanah in September or October, not in Nisan.
With your numbers
- The year begins on 1 Tishri; its date is set from the mean new moon and then moved by the postponement rules
- A Hebrew day begins at nightfall, so the evening before the Gregorian date shown already counts as this Hebrew date
Quick reference
A Hebrew date begins at nightfall the evening before. Festivals outside Israel may add a second day; the page converts dates and does not list observances.
| Example | Result |
|---|---|
| 4 October 2026 | Hebrew date: 23 Tishri 5787 AM |
| 1 Tishri 5788 (Rosh Hashanah) | Gregorian date: October 2, 2027 |
| 10 Tishri 5788 (Yom Kippur) | Gregorian date: October 11, 2027 |
| 25 Kislev 5787 (Hanukkah) | Gregorian date: December 5, 2026 |
| 14 Adar 5788 (Purim) | Gregorian date: March 12, 2028 |
| 15 Nisan 5787 (Passover) | Gregorian date: April 22, 2027 |
| 14 Adar II 5790 (Purim, leap year) | Gregorian date: March 19, 2030 |
| 1 January 2027 | Hebrew date: 22 Tevet 5787 AM |
Common questions about the Hebrew Date Converter
- Why is there an Adar I and an Adar II?
- Twelve lunar months are about 11 days shorter than a solar year, so the Hebrew calendar adds a thirteenth month in 7 years of every 19 to keep Passover in spring. The added month comes before Adar. In those leap years the two are called Adar I and Adar II, and Purim is kept in Adar II.
- Which years are leap years?
- Years 3, 6, 8, 11, 14, 17 and 19 of each 19-year cycle. Arithmetically, a year is a leap year when (7 × year + 1) divided by 19 leaves a remainder below 7.
- Why can a Hebrew year be 353, 354, 355, 383, 384 or 385 days long?
- Rosh Hashanah is set from the mean new moon and then postponed by a day or two by four rules, so that Yom Kippur never falls next to Shabbat and Hoshana Rabbah never falls on Shabbat. To absorb those postponements, Heshvan and Kislev can each have 29 or 30 days. A year with both at 29 is called deficient, with Heshvan 29 and Kislev 30 regular, and with both at 30 complete.
- When does a Hebrew date begin?
- At nightfall. Calendars print each Hebrew date beside the Gregorian day it mostly covers, and so does this page, so a Shabbat or festival begins on the evening before the Gregorian date shown.
- How do I find my Hebrew birthday?
- Convert your Gregorian birth date to find its Hebrew date. If you were born after nightfall, use the next Gregorian day. Then convert that Hebrew day and month back to Gregorian in the year you want. For a birthday in Adar of a common year, families differ on whether to keep it in Adar I or Adar II in a leap year, so ask whoever you follow.
- Does the page show holidays?
- No, it converts dates. The festival dates in the quick reference are just Hebrew dates converted to Gregorian. Outside Israel several festivals add a second day, which the page does not list.