Which calendar this page uses
The page uses the Umm al-Qura calendar, the official civil calendar of Saudi Arabia. It is a calculated calendar, so each month's length is known in advance, and it is the calendar most Gulf government and business documents follow when they show a Hijri date. The Hijri date is worked out in your browser from your device's own date, so it updates at midnight where you are.
Why the date can differ by a day
Religious months such as Ramadan, Shawwal and Dhu al-Hijjah start when the new crescent moon is sighted, and each country announces this officially. The UAE, Saudi Arabia, Oman and other countries can start a month on different days, and a sighting can differ from the calculated calendar. For the start of Ramadan, Eid al-Fitr, Eid al-Adha or the day of Arafah, always follow your country's official announcement.
How the Hijri calendar works
The Hijri calendar is lunar. Each month has 29 or 30 days, so a Hijri year has 354 or 355 days, about 11 days shorter than the Gregorian year. That is why Ramadan and the Eids move earlier each Gregorian year. The calendar counts years from the Hijrah, the Prophet's migration from Makkah to Madinah in 622 CE, and years are marked AH (after the Hijrah).
The twelve Hijri months
The months in order are Muharram, Safar, Rabi al-Awwal, Rabi al-Thani, Jumada al-Ula, Jumada al-Akhirah, Rajab, Sha'ban, Ramadan, Shawwal, Dhu al-Qadah and Dhu al-Hijjah. Muharram, Rajab, Dhu al-Qadah and Dhu al-Hijjah are the four sacred months. To convert any other date, use the Hijri date converter.