Historical Hijri date converter
Convert any date between the Hijri and Western calendars from 1 AH (622 CE) to today — for history, manuscripts, Ottoman documents, family records and research. Each result says which calendar was used, so you can cite it.
Quick Date Converter
Before 1300 AH (1882 CE) there is no Umm al-Qura calendar, so we use the arithmetical (tabular) Islamic calendar that historical references use. It can differ by a day or two from when the crescent was actually sighted.
Before 15 October 1582, Christian-era dates are given in the Julian calendar, as historical sources record them.
How the converter calculates
- From 1 Muharram 1300 AH (12 November 1882) onward: the Umm al-Qura calendar, Saudi Arabia’s official calendar, as Apple, Android and Windows show it.
- Before 1300 AH: the arithmetical (tabular) Islamic calendar, whose first day, 1 Muharram 1 AH, is Friday 16 July 622 CE. It is the calendar historical references and tables use.
- Before 15 October 1582: Christian-era dates are given in the Julian calendar, as historical sources record them, with the Gregorian equivalent underneath.
Examples worked out by this converter
| Event | Western date | Hijri date | Weekday |
|---|---|---|---|
| Start of the Hijri calendar | 16 July 622 CE (Julian) | 1 Muharram 1 AH | Friday |
| Battle of Hattin | 4 July 1187 CE (Julian) | 25 Rabiʿ II 583 AH | Saturday |
| Battle of Ain Jalut | 3 September 1260 CE (Julian) | 25 Ramadan 658 AH | Friday |
| Fall of Constantinople | 29 May 1453 CE (Julian) | 20 Jumada I 857 AH | Tuesday |
| Fall of Granada | 2 January 1492 CE (Julian) | 1 Rabiʿ I 897 AH | Monday |
| Battle of the Pyramids | 21 July 1798 CE | 7 Safar 1213 AH | Saturday |
| First day of the Umm al-Qura table | 12 November 1882 CE | 1 Muharram 1300 AH | Sunday |
Why a result can be a day or two off
Hijri months began with the sighting of the crescent, which varied by place and by year. The tabular calendar is a fixed convention historians share, but it cannot know what was actually seen on a given evening.
Some converters count from Thursday 15 July 622 (the astronomical epoch) instead of Friday, so their results differ from ours by one day.
If your source names the day of the week, compare it with the result: the weekday is the best evidence for the right date.
A quick estimate without a converter
A Hijri year is about 11 days shorter than a Gregorian one, so:
- CE year ≈ 622 + AH year × 0.97
- AH year ≈ (CE year − 622) × 1.03
Example: 857 AH ≈ 622 + 831 = 1453 CE.
What it does not cover
It does not convert the Ottoman Rumi (fiscal) calendar or the solar Hijri (Iranian) calendar. For a date before the Hijra it tells you the date is earlier than the start of the Hijri calendar.
How to cite a result
For example: “Converted with the tabular Islamic calendar (Friday epoch) and the Julian calendar, islamicdates.org, accessed …”. The method is described on our About & methodology page.