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Date Converter
Gregorian to and from the world's main calendars, using the same calendar data as your phone.
From a Gregorian date
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From another calendar
About these calendars
- Islamic (Hijri): purely lunar, 12 months of 29 or 30 days, so it moves about 11 days earlier each Gregorian year. Ramadan cycles through all seasons in about 33 years.
- Hebrew: lunisolar. A 13th month (Adar I) is added 7 times in every 19 years to keep Passover in spring.
- Persian (Solar Hijri): the official calendar of Iran and Afghanistan; the year starts at the March equinox (Nowruz).
- Chinese: lunisolar, used to set Lunar New Year and traditional festivals. Years are named in a 60-year cycle.
- Julian: the calendar of Julius Caesar, still used liturgically by several Orthodox churches; currently 13 days behind.
Converters like this one use a calculated Hijri table, but traditionally a month opens on the evening a thin crescent is first spotted after the new moon, which is why announcements can differ by a day from country to country. Why the Moon goes dark and returns at all is the subject of a narrated explainer on ahaboo.
Questions people ask
How do I convert a Gregorian date to the Hijri (Islamic) date?
Enter the date in the first box. The Hijri date uses the Umm al-Qura calendar (Saudi Arabia's official tabular calendar). Religious observances in many countries follow local moon sighting, which can differ by a day.
How do I convert a Hebrew or Hijri date back to Gregorian?
Use "From another calendar": choose the calendar, year, month and day, and the Gregorian date appears. Remember Hebrew and Islamic days begin at sunset, so an evening event belongs to the next day in those calendars.
Where does the conversion data come from?
From your browser's built-in internationalisation data (the Unicode CLDR/ICU calendars that also power phones and operating systems). The Julian calendar and Julian Day are calculated with standard astronomical formulas.
What is the difference between the Julian and Gregorian calendars?
The Julian calendar has a leap year every four years without exception, so it runs slow. The gap is 13 days from 1 March 1900 until 28 February 2100. Countries switched at different times: Catholic Europe in 1582, Britain and its colonies in 1752, Russia in 1918.