How to use the gregorian to hijri date converter
- Pick the Gregorian date you want to convert. The date field starts on today and accepts any day from 1900 to 2100.
- Choose the Hijri calendar: Umm al-Qura, which is based on astronomical calculation, or Civil (tabular), which follows a fixed arithmetic rule.
- Tick It is after sunset if you are converting an evening time, because a Hijri day begins at sunset and the evening already belongs to the next Hijri date.
- Read the Hijri day, month and year, the length of that month, and the date in the other Hijri calendar. A warning appears when the two calendars disagree.
Formula
Hijri date = the Hijri calendar date of the Gregorian day, as given by the calendar data built into your browser
After sunset: convert the next Gregorian day instead
Civil (tabular) rule: months alternate 30 and 29 days, and 11 years in every 30 add a day to the last month
The conversion is done by your browser with its Intl calendars. The tool does not contain a calendar table of its own, so results follow the data in your browser.
Worked examples
March 1, 2025 is 1 Ramadan 1446 AH in the Umm al-Qura calendar, and Ramadan 1446 has 29 days in that calendar. March 30, 2025 is 1 Shawwal 1446 AH in Umm al-Qura but 30 Ramadan 1446 AH in the Civil (tabular) calendar, so the two calendars are a day apart and the tool shows a warning.
For March 29, 2025 with It is after sunset ticked, the tool converts March 30 instead and returns 1 Shawwal 1446 AH. The civil calendar results were checked against a separate Python implementation of the arithmetic rule on twelve dates between 1900 and 2100, and they matched.
Why Hijri dates can differ by a day
The Hijri calendar is a lunar calendar with 12 months of 29 or 30 days, so a year is about 354 days. Traditionally a month begins when the new crescent moon is sighted, which depends on the weather and on where you are. Because of that, a country, a community or a mosque may start a month one day before or after another. The date from this page is a calculation, not an announcement.
The Umm al-Qura calendar sets month starts by astronomical rules and is widely used for civil dates in Saudi Arabia. The tabular calendar is a simple arithmetic approximation that is handy for software because it can be calculated for any date, but it can be one or two days away from the moon. For a religious observance such as the start or end of Ramadan, follow your local religious authority.
Browser data and range
Your browser supplies the calendar data. Current versions of Chrome, Edge, Firefox and Safari include it, and results can differ slightly between browsers and versions. The range is limited to the years 1900 to 2100, where the data is dependable. Dates before that, and holiday names or prayer times, are not calculated here.
Related tools include the Hebrew date converter, the date calculator and the day of the week calculator.
Assumptions and limits
- Results come from your browser calendar data and can differ between browsers and from local moon sighting by a day.
- The conversion goes from Gregorian to Hijri only, for dates from the year 1900 to 2100.
- The after-sunset option adds one day. It does not calculate the time of sunset for your place.
- Holidays, prayer times and the start of Ramadan or Eid are not calculated. Use your local religious authority for those.
Frequently asked questions
Why is the Hijri date here different from the one my community uses?
Months traditionally start with a moon sighting, which can vary by place, so communities may differ by a day. This page calculates the date from calendar data and cannot know which day your community announced.
Which Hijri calendar should I choose?
Umm al-Qura follows astronomical rules and is the closer match for the moon in most cases. The tabular calendar uses a fixed arithmetic pattern. Compare them with the warning the tool shows, and follow local guidance for observances.
What does AH mean?
AH stands for Anno Hegirae, the Latin name for the Hijri era, which counts years from the migration of the Prophet Muhammad from Mecca to Medina in 622 CE.
Why does a Hijri day begin at sunset?
In the Islamic calendar each day runs from sunset to sunset. That is why the tool has an after sunset option: an evening time already belongs to the next Hijri date.