Hijri ↔ Gregorian Date Converter

About This Tool

This Hijri–Gregorian converter uses the tabular Islamic calendar algorithm — a mathematically precise, internationally recognised standard used by government institutions and academic bodies across the Arab world. It is described as "computational" (حسابي) to distinguish it from the observational calendar (استهلالي) that relies on actual moon-sighting. The computational approach allows dates to be predicted with mathematical certainty, while the observational calendar may differ by a day depending on astronomical viewing conditions. Many countries including Saudi Arabia, the UAE, and Kuwait rely on the Hijri calendar for official documents, employment contracts, and legal procedures. The twelve Hijri months are: Muharram, Safar, Rabi al-Awwal, Rabi al-Thani, Jumada al-Awwal, Jumada al-Akhira, Rajab, Sha'ban, Ramadan, Shawwal, Dhu al-Qi'dah, and Dhu al-Hijjah. All conversions happen locally in your browser; no data is sent to any server. For more conversion tools, try the Unit Converter.

The Hijri calendar plays a central role in both the religious and practical lives of Muslims worldwide. It is used to determine the timing of major acts of worship: the start of Ramadan for fasting, Laylat al-Qadr, Eid al-Fitr, the Hajj pilgrimage season in Dhu al-Hijjah, and Eid al-Adha. Because the Hijri year is purely lunar — composed of 12 months of 29–30 days each — it is approximately 11 days shorter than the Gregorian year. As a result, Ramadan advances by roughly 11 days each Gregorian year, cycling through all seasons over a period of about 33 years. This drift means that memorising Hijri birth dates or calculating ages in Hijri years requires a reliable conversion tool every time. Four of the twelve Hijri months hold special sacred status — known as the forbidden months (أشهر الحرم): Dhu al-Qi'dah, Dhu al-Hijjah, Muharram, and Rajab; these were honoured even in pre-Islamic Arabia as months of peace and pilgrimage. On a practical level, Saudi Arabia uses the Hijri calendar for government pay cycles, national identity documents, official correspondence, and employment contracts — making accurate conversion an everyday need for residents and employees. The tool also handles historical dates going back many centuries, making it useful for Islamic history researchers and manuscript scholars who need to cross-reference medieval Hijri dates with their Gregorian equivalents.