How the Hebrew calendar works
The Hebrew calendar follows the moon for its months and the sun for its seasons. Each month begins near the new moon and lasts 29 or 30 days. Twelve lunar months come to about 354 days, eleven short of a solar year, so a thirteenth month is added in years 3, 6, 8, 11, 14, 17 and 19 of every 19-year cycle. That keeps Pesach in the spring, as the Torah requires.
Years are counted from the traditional date of creation. The civil year 2026 begins in Hebrew year 5786 and, from Rosh Hashana in the autumn, continues in 5787.
The months
| Month | Hebrew | Days | Usually falls in |
|---|---|---|---|
| Tishrei | תשרי | 30 | Sep – Oct |
| Cheshvan | חשון | 29 / 30 | Oct – Nov |
| Kislev | כסלו | 29 / 30 | Nov – Dec |
| Tevet | טבת | 29 | Dec – Jan |
| Sh'vat | שבט | 30 | Jan – Feb |
| Adar (Adar I) | אדר (אדר א׳) | 29 (30) | Feb – Mar |
| Adar II | אדר ב׳ | 29 | Mar – Apr |
| Nisan | ניסן | 30 | Mar – Apr |
| Iyyar | אייר | 29 | Apr – May |
| Sivan | סיון | 30 | May – Jun |
| Tamuz | תמוז | 29 | Jun – Jul |
| Av | אב | 30 | Jul – Aug |
| Elul | אלול | 29 | Aug – Sep |
Why Cheshvan and Kislev change length
Rosh Hashana may not fall on a Sunday, Wednesday or Friday, which keeps Yom Kippur off Friday and Sunday and Hoshana Raba off Shabbat. To make the dates fit, a day is added to Cheshvan or taken from Kislev, giving years of 353, 354 or 355 days (383 to 385 in a leap year).
Writing a Hebrew date
Hebrew dates are often written with letters instead of digits. Each letter has a value: א is 1, י is 10, ק is 100. The year 5787 is usually written תשפ״ז, leaving out the thousands. The converter shows both forms so you can copy whichever you need for an invitation, a ketubah or a headstone.
Questions people ask
Why does the Hebrew date change at sunset?
In the Jewish calendar a day runs from sundown to sundown, following Genesis: “there was evening and there was morning.” A child born on a Tuesday evening after sunset has the Hebrew birthday of Wednesday. Choose After sunset in the converter for anything that happened in the evening.
How do I convert a Hebrew date to an English date?
Switch the converter to Hebrew → Gregorian, enter the day, month and Hebrew year (for example 3 Kislev 5787), and the civil date appears straight away, along with the evening the Hebrew date begins.
What is the current Hebrew year?
Today falls in the Hebrew year 5787 (תשפ״ז). The number changes on Rosh Hashana in September or early October. To get the Hebrew year, add 3760 to the civil year, or 3761 from Rosh Hashana to 31 December.
What is a Jewish leap year?
The Hebrew calendar follows the moon but must keep step with the seasons, so 7 years in every 19 get a 13th month. In a leap year Adar is doubled into Adar I and Adar II, and Purim falls in Adar II.
How accurate is this converter?
It applies the fixed rules of the Hebrew calendar (the molad and the four postponements) and is tested day by day against Hebcal for the years 1700 to 2300 with no differences. Holidays, Torah portions, yahrzeits and birthdays are checked the same way.
Are dates before 1582 supported?
Yes, in the proleptic Gregorian calendar. Documents from before 1582, and later in some countries, use the Julian calendar, which differs by 10 or more days.