Tabular Islamic (civil) to Gregorian date converter
Useful for converting Hijri dates in historical references and software that use the arithmetic calendar rather than sighting or Umm al-Qura.
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How to use it
- Enter hijri year, month and day.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
JDN = day + ceil(29.5 × (month minus 1)) + 354 × (year minus 1) + floor((3 + 11 × year) / 30) + 1948439, then converted to a Gregorian date with the standard algorithm.
Example
Inputs: Hijri year = 1,448, Month = 4. Rabi al-Thani, Day = 18. Result: Gregorian date: Thursday, October 1, 2026 (2026-10-01); Weekday: Thursday; Written out: 1 October 2026.
Limits and caveats
- It can differ by one or two days from Umm al-Qura and moon sighting.
- Accepts years 1318 to 1523 (about 1900 to 2100).
Questions about this tool
Why is day 30 rejected for Safar?
Even months always have 29 days in the tabular calendar, except Dhu al-Hijjah in a leap year.
How do I know if a tabular Hijri year is a leap year?
If (14 + 11 × year) mod 30 is less than 11, it is a leap year, as with 1445.
What date is 1 Muharram 1446 in this calendar?
Monday 8 July 2024, while the Umm al-Qura calendar had Sunday 7 July.