☪️ Hijri (Islamic) Calendar Converter

The Hijri calendar is a purely lunar calendar used throughout the Islamic world, counting years from the Hijra (Muhammad's migration from Mecca to Medina in 622 CE). A year has 12 months and about 354-355 days, shorter than a Gregorian year, so Hijri dates shift roughly 11 days earlier relative to the Gregorian calendar each year. It is used to set the dates of Islamic religious observances such as the fasting month of Ramadan (month 9).

Gregorian → Hijri: the tool first tries the browser's Intl.DateTimeFormat API with calendar: 'islamic-umalqura' (Saudi Arabia's official Umm al-Qura calendar, based on astronomical calculation). If the browser doesn't actually support it and silently substitutes a different calendar (detected by checking resolvedOptions().calendar), it falls back to calendar: 'islamic-civil' (a tabular calendar based on fixed arithmetic rules).

Hijri → Gregorian: there's no standard API for a direct reverse conversion, so the tool estimates a Gregorian date near the given Hijri year, then steps day-by-day forward and backward, converting each candidate back to Hijri and comparing it against your input (bounded to at most 800 iterations), until it finds the exact matching date.

Both the Umm al-Qura and Islamic civil calendars used by this tool are calculated (arithmetic) calendars. They may differ by up to ±1 day from the practice, used by some countries, regions, and religious authorities, of determining the start of each month by actual naked-eye moon sighting. If you need an exact date for religious purposes, check your local authority's official announcement as well.