How to use it
- Choose Gregorian to Hijri or Hijri to Gregorian.
- For Gregorian to Hijri, type the date as year-month-day. The Hijri day, month name, year and weekday appear below.
- For Hijri to Gregorian, enter the Hijri year, pick the month and enter the day. The Gregorian date and its weekday appear.
How it works
The Gregorian to Hijri direction asks the browser’s Intl.DateTimeFormat for the islamic-umalqura calendar and reads the year, month and day. There is no formula for the reverse direction, so the tool estimates the Gregorian day from the average lengths of a Hijri year (354.37 days) and month (29.53 days), then checks the days around the estimate until one converts back to exactly the date you entered. If none does, that day does not exist in that month.
Worked example
3 November 2026 is 23 Jumada al-awwal 1448 AH, a Tuesday. In the other direction, 1 Ramadan 1446 AH is Saturday, 1 March 2025, and 30 Ramadan 1446 does not exist because that month had 29 days: 1 Shawwal 1446 was 30 March 2025.
Tips
- Check religious observances such as the start of Ramadan with your local moon-sighting authority; this tool shows the calculated calendar.
- A Hijri day starts at sunset, while the converter works with whole calendar days.