Dates and Days

Hebrew calendar

Your Hebrew birthday, and the civil date it lands on each year

—

Use what you know about the time of day. This page does not request your location and does not calculate sunset; if you are not sure, it shows both possible Hebrew dates.

The years ahead (each Hebrew day begins at sunset the evening before)
Birth-time caseHebrew dateCivil dateBegins evening ofConvention
How this was counted
Hebrew date of birth— Born in a leap year— Next occurrence— Years needing a convention—
Family list, kept in this browser only

    Saved in this browser’s local storage, never uploaded. Export makes a file you can import on another device.

    Checked on every build against a second implementation built on the ICU library's Hebrew calendar. How it is checked

    Enter a date to get its Hebrew date and the civil date it falls on in each Hebrew year ahead: a birthday, an anniversary or a yahrzeit, or the date of a bar or bat mitzvah. A Hebrew day begins at sunset, so the page asks whether it was after sunset. Add to calendar saves every year in the table in one file.

    The Hebrew date stays fixed and the civil date moves

    Twelve lunar months come to about eleven days less than a solar year. Left alone, the calendar would drift a whole season in a decade, so a thirteenth month is inserted seven times in every nineteen years. The civil date of a Hebrew birthday therefore falls about eleven days earlier in most years, then jumps about nineteen days later when the extra month arrives. Over a run of years it stays within a band about four weeks wide, and the table lists the civil date for each year so you do not have to convert them one year at a time.

    The day starts the evening before

    A Hebrew birthday begins at sunset on the evening before the civil date most calendars print, and runs to sunset on that date. Ordinary usage usually means the evening; software usually means the daytime date. The table above gives both, in the Civil date and Begins evening of columns. If you are arranging anything around the date, say which of the two you mean.

    The months that sometimes run short

    Cheshvan and Kislev each run 29 or 30 days, which is how the calendar lands its festivals on permitted weekdays, so a 30th of either is missing in some years. For a birthday or anniversary the table gives both customs, named: the last day of the short month, and the first day of the next. A yahrzeit for a death on the 30th follows the first anniversary: if that year had a 30th, it is kept on the 30th, or on the 1st of the next month when the month is short; if it had none, it is kept on the last day of the month every year.

    Adar, and the year with two of them

    A leap year has Adar I and Adar II. For a birthday or anniversary from the single Adar of a common year, customs differ: Adar II, the month before Nisan, or Adar I, the same month number. The table lists both. A bar mitzvah (at 13) or bat mitzvah (at 12) is placed by the usual rule: a birth in Adar of a common year, or in Adar II, is kept in the last Adar of the year; a birth in Adar I stays in Adar I, or in Adar when there is only one. A yahrzeit for a death in Adar of a common year is kept in Adar I in a leap year (some also keep Adar II); a death in Adar II is kept in Adar II, or in Adar; and a death on 30 Adar I is kept on 30 Shevat in a year with one Adar. Each row says which rule placed it.

    Which practice is yours

    The yahrzeit and bar or bat mitzvah rules are those of Calendrical Calculations (Reingold and Dershowitz), which published Jewish calendars such as Hebcal also use, and they are checked against a second, independent implementation. Where a family or community custom differs, follow it. The dates are exact integer arithmetic from the calendar’s own rules; see the methodology and the Hebrew calendar converter.

    Questions

    What is my Hebrew birthday?
    It is the Hebrew date you were born on, which the tool above works out from your civil date of birth. Because the Hebrew calendar is lunisolar and the civil one is not, that Hebrew date lands on a different civil date almost every year, within a band about four weeks wide. The table shows where it falls in each of the years ahead.
    Why does my Hebrew birthday move around the civil calendar?
    A Hebrew year is twelve lunar months, which runs about eleven days short of a solar year. A thirteenth month is added seven times in every nineteen to stop the calendar drifting through the seasons. Your Hebrew date is fixed; the civil date it maps to comes earlier in most years and jumps later once an extra month has been added.
    How does being born after sunset change my Hebrew birthday?
    A Hebrew day starts at local sunset. If you know you were born before sunset, choose No and the civil date maps to that daytime Hebrew date. If you know you were born after sunset, choose Yes and the tool advances to the next Hebrew date. If you are not sure, choose Not sure and it shows both possibilities. The page does not request your location or calculate a sunset time; it uses the answer you select.
    What happens if I was born on 30 Cheshvan or 30 Kislev?
    Those months run either 29 or 30 days depending on the year, so in a short year the date does not exist at all. Two practices are in use: keeping the birthday on the last day of the short month, or moving it to the first day of the month that follows. The table prints both, with their names, for every such year in the range you select.
    I was born in Adar. Which Adar is my birthday in a leap year?
    A leap year has two, Adar I and Adar II, and a birthday from an ordinary Adar has to go in one of them. Both practices are followed: Adar II keeps the birthday in the month immediately before Nisan, while Adar I keeps the same month number. The two dates fall about a month apart, so the table shows both, labelled, for every leap year in the range.