Calendar comparison
Difference Between Hijri and Gregorian Calendars
Discover how the lunar Hijri calendar and the solar Gregorian calendar differ in month length, year structure, and practical use.
Lunar versus solar
The Hijri calendar is based on the moon cycle, while the Gregorian calendar follows the Earth’s orbit around the Sun. That means a Hijri year is about 11 days shorter.
Month structure
Hijri months have 29 or 30 days depending on the moon sighting, while Gregorian months have a fixed pattern of 28–31 days.
How the calendars are used together
Hijri dates are useful for Islamic observances and lunar anniversaries, while Gregorian dates are common for civil administration, school, work, and travel. A date converter helps compare the two without treating either calendar as a substitute for the other.
Why dates move each year
Since the Hijri year is shorter, holidays like Ramadan and Eid shift earlier in the Gregorian calendar each year.
Using both calendars together
When planning events or studying history, convert between Hijri and Gregorian dates with the Hijri and Gregorian converter and read how to convert Hijri to Gregorian dates. Calculated results may differ by approximately one day from a locally announced lunar date.