Hijri to Gregorian Converter

The Umm al-Qura calendar (تقويم أم القرى) is the official administrative Islamic calendar used by Saudi Arabia. It is based on astronomical calculations with Mecca (Umm al-Qura, meaning "Mother of Cities") as the reference point. Unlike traditional Islamic calendars that rely on physical moon sighting, Umm al-Qura uses predetermined computational rules to estimate the beginning of each lunar month, making it predictable for civic and administrative planning.

This converter uses the well-established Umm al-Qura computational algorithm, which is accurate for administrative and planning purposes. The Gregorian output is precise to the day. However, because the actual Islamic calendar depends on physical lunar crescent observation (which can be affected by weather, atmospheric conditions, and geographic location), the converted Hijri date may differ by ±1 day from what is observed in some regions. For religious events like Ramadan or Eid, always verify with local authorities.

The Islamic Hijri calendar is a lunar observation calendar — each month begins only after the new crescent moon (hilal) is physically sighted. The Umm al-Qura algorithm estimates this based on astronomical calculations assuming ideal conditions. In practice, crescent visibility depends on humidity, dust, cloud cover, and the observer's location. Different countries and communities may also follow different sighting criteria or rely on announcements from specific religious bodies, leading to regional variations of 1–2 days.

The Gregorian calendar is a solar calendar with 365 days per year (366 in leap years), based on Earth's orbit around the Sun. The Hijri (Islamic) calendar is a pure lunar calendar with approximately 354 days per year, based on the Moon's phases. This means Hijri dates shift backward by about 10–12 days each Gregorian year relative to the seasons. The Hijri calendar began in 622 CE with the Hijra (migration) of Prophet Muhammad ﷺ from Mecca to Medina.

The Umm al-Qura calendar is the official administrative calendar of Saudi Arabia. It is used for government documents, civil planning, salary schedules, and official date-stamping. Several other Gulf and Islamic countries reference it for administrative convenience. However, for religious purposes (such as determining the start of Ramadan, Eid al-Fitr, Eid al-Adha, and Hajj), Saudi Arabia and many other countries still rely on actual moon sighting or official religious council announcements.

The 12 Islamic months are: 1. Muharram (sacred month), 2. Safar, 3. Rabi' al-Awwal (birth month of the Prophet ﷺ), 4. Rabi' al-Thani, 5. Jumada al-Ula, 6. Jumada al-Akhirah, 7. Rajab (sacred month), 8. Sha'ban, 9. Ramadan (month of fasting), 10. Shawwal (Eid al-Fitr), 11. Dhu al-Qi'dah (sacred month), 12. Dhu al-Hijjah (month of Hajj and Eid al-Adha, sacred month). Four months are considered sacred: Muharram, Rajab, Dhu al-Qi'dah, and Dhu al-Hijjah.

This converter provides Umm al-Qura estimates, which are widely used as a reference. However, the actual start of Ramadan, Eid al-Fitr, and Eid al-Adha are determined by physical moon sighting or official announcements from religious authorities in your country. The Umm al-Qura estimate is usually very close (within 0–1 days of Saudi Arabia's official announcement), but always confirm with your local mosque or Islamic council for religious observance purposes.

"Umm al-Qura" (أم القرى) is an Arabic phrase meaning "Mother of Cities" or "Mother of Villages." It is a honorific title for the city of Mecca (Makkah), the holiest city in Islam, located in Saudi Arabia. The calendar is named after Mecca because the city serves as the spiritual center of the Islamic world and the reference point for the calendar's astronomical calculations.

This converter supports Hijri years from 1 AH (622 CE) up to approximately 1600 AH (≈2180 CE), and Gregorian years from 622 CE onward. For dates before 1 AH (prior to the Hijra), the Islamic calendar is not historically applied, so conversion is not meaningful. The Umm al-Qura algorithm itself was formalized in modern times but retroactively models the lunar calendar back to the first Hijri year.

The Umm al-Qura calendar is one implementation of the Islamic Hijri calendar. While it follows the same lunar structure (12 months, ~354 days), it relies on astronomical computation rather than physical moon sighting. The traditional Islamic Hijri calendar is observation-based. In practice, the Umm al-Qura calendar closely mirrors the traditional calendar and is used interchangeably for most administrative and everyday purposes in Saudi Arabia and beyond.