How to use it
- Choose Gregorian date to Hijri and type the day in Gregorian date, or choose Hijri date to Gregorian and type the Hijri date as year-month-day in Hijri date.
- Choose the Calendar: Umm al-Qura for the calendar Saudi Arabia uses, or the civil calendar for the arithmetic one.
- Read the Converted date and the Weekday of the Gregorian date.
- Open Days of this Hijri month to see the Gregorian date of every day of that month, and whether it has 29 or 30 days.
How the two calendars work
The Hijri calendar is a lunar calendar. Each month begins when the new crescent is seen or, in a calculated calendar, when the rule says it begins. A month has 29 or 30 days, and a year is about 354 days.
The Umm al-Qura calendar is the calendar Saudi Arabia uses for civil purposes. Its dates are set by the Institute of Astronomical and Geophysical Research in Riyadh. Since 1423 AH (2002) the rule is this: on the 29th day of a month, the next day begins the new month only if the conjunction happens before sunset and the moon sets after the sun. Otherwise the month lasts 30 days.
The civil calendar is a fixed arithmetic rule with a 30-year cycle. It does not follow the moon, so it is an approximation. The converter uses the same arithmetic to find the Gregorian day of a typed Hijri date, and then checks the day against the calendar.
Turkish religious dates and Umm al-Qura
In Turkey the religious days, such as Ramazan Bayramı and Kurban Bayramı, are the dates in the religious days list of the Diyanet İşleri Başkanlığı (the Presidency of Religious Affairs). That list is not always the same as the Umm al-Qura table, and the two can differ by a day.
The reason is that the real start of a Hijri month depends on the sighting of the new moon. This page can compute only the calendar rule. For the binding Turkish date, use the Diyanet list.
What this converter does not cover
- The sighting: the real start of a month where you live may be a day earlier or later than the table.
- Years outside 1300 to 1600 AH: the Umm al-Qura table does not cover them, so such dates are refused.
- Times of day: the converter counts whole days and does not say whether a religious day begins in the evening or the morning.
Worked example: 10 November 2026 in two calendars
Choose Gregorian date to Hijri, type 10 November 2026 and keep the calendar on Umm al-Qura. The converted date is Jumada I 30, 1448 AH, and the day is a Tuesday.
In Umm al-Qura, Jumada I 1448 begins on 12 October 2026 and has 30 days, so 10 November is its last day. Jumada II begins the next day.
Switch the calendar to Civil and the same day becomes Jumada I 29, 1448 AH: the civil calendar is one day behind here.
| Calendar | Hijri date of 10 November 2026 |
|---|---|
| Umm al-Qura | Jumada I 30, 1448 AH |
| Civil | Jumada I 29, 1448 AH |
Frequently asked questions
Why do the Umm al-Qura and civil dates differ?
They are two rules for the same lunar calendar. Umm al-Qura follows the Saudi astronomical rule, and the civil calendar is a fixed arithmetic cycle that does not follow the moon, so they can differ by a day in some months.
Are these the dates of Ramadan and Eid in Turkey?
Not necessarily. In Turkey the religious dates are set and published by the Diyanet İşleri Başkanlığı. They can differ from the Umm al-Qura table by a day, so for Turkey use the Diyanet list.
Why does a Hijri month have 29 or 30 days?
A month begins with the new moon, and the moon takes about 29.5 days to go round the Earth. Each month therefore has 29 or 30 days, and the month table shows which one the chosen calendar gives.
Why can I not convert a date before 1882 or after 2174?
The Umm al-Qura table covers the Hijri years 1300 to 1600, which run from 12 November 1882 to 25 November 2174. Outside that span the converter refuses the date rather than guess.
Is the date I type sent to a server?
No. The conversion runs in your browser. Nothing you type is sent to us or stored, and you can use the page without an account.
Sources
- Umm al-Qura dates of Ramadan and Shawwal, 1445 to 1447 AH: table by van Gent, Utrecht University
- Umm al-Qura month-start rule since 1423 AH: van Gent, Utrecht University
- Diyanet İşleri Başkanlığı: 2026 religious days list
- Diyanet İşleri Başkanlığı, Presidency of Religious Affairs
Figures and text last checked on Tuesday, November 10, 2026.