How Many Days Until

How we calculate dates

Where every date on this site comes from, how the days remaining are counted, and the limits of the accuracy we can promise.

The calendar we use: Umm al-Qura

We use the Umm al-Qura calendar, the official civil calendar of Saudi Arabia. It is computed astronomically years in advance, which is why we can show Ramadan and Eid dates for the next ten years.

Data sources

  1. UmmahAPI: a Hijri and Gregorian conversion service that calculates with the Umm al-Qura calendar. We ask it for the Gregorian date of each occasion: 1 Ramadan, 1 Shawwal, 9 and 10 Dhu al-Hijjah, and the others.
  2. ICU tables: an open-source software library that includes the Umm al-Qura tables. We check every date from the first source against it, and if the two disagree we review the date by hand before publishing. It is also our fallback if the service is unavailable.

Expected and confirmed

A calculated date is labelled "expected". The start of Ramadan, Shawwal and Dhu al-Hijjah is established by looking for the crescent on the evening of the 29th of the previous month. When the official announcement is made in Saudi Arabia, we enter the announced date and change the label to "confirmed". After that, no automatic update replaces it.

Other countries may announce a date that differs by one day. We show the Umm al-Qura date and point out this possibility on every page.

How the days remaining are counted

The count is the difference in calendar days between today and the date of the occasion, not including today. It is first calculated in Makkah time, then recalculated in your browser using your device's time zone. The hours and minutes ticker counts down to the midnight that begins the day of the occasion.

Religiously, the Hijri day begins at sunset, so night occasions such as Laylat al-Qadr begin on the evening before. Their pages say so and show the date of that evening.

Limits of accuracy

  • The observed date can differ from the expected one by a day, depending on the moon sighting.
  • We do not show prayer times or fasting start and end times, which depend on the city.
  • The Hijri age column in the age table is approximate. The Hijri age calculator gives the exact figure.

Frequently asked questions

Which calendar does this site use?
The Umm al-Qura calendar, the official calendar of Saudi Arabia.
When does a date change from "expected" to "confirmed"?
When the official moon-sighting announcement is made. We then enter the announced date by hand.
Why is your date different from the one in my country?
Some countries use a local moon sighting or a different astronomical criterion, so they can run a day ahead of or behind the Umm al-Qura calendar.

Where the dates come from Hijri dates are calculated with the Umm al-Qura calendar through UmmahAPI and cross-checked against the Umm al-Qura tables in the ICU library. Islamic months officially begin with the sighting of the crescent, so the observed date can differ by one day from country to country.