How it is calculated
The converter uses the Umm al-Qura calendar, the official calendar of Saudi Arabia, which is computed astronomically in advance for each month.
A Hijri month has 29 or 30 days and a Hijri year 354 or 355 days, so there is no fixed offset between the calendars — the matching date moves about 11 days each year.
Countries that rely on local moon sighting (such as Morocco) may start a month a day later than Umm al-Qura, especially Ramadan and Eid.
Worked example
1 Ramadan 1447 AH corresponds to about 18 February 2026 in Umm al-Qura, and 21 October 2026 is about 10 Jumada al-Ula 1448 AH.
Frequently asked questions
Why does my local Hijri date differ by a day?
Some countries follow local moon sighting, while this converter uses the astronomically computed Umm al-Qura calendar.
How are Hijri and Gregorian months different?
Hijri months are lunar (29 or 30 days) and begin with the new crescent; Gregorian months are solar (28–31 days).
How many days are in a Hijri year?
354 or 355 — about 11 days shorter than a Gregorian year.
What range is supported?
Modern browsers support Umm al-Qura accurately from about 1300 AH to 1600 AH.