β Islamic calendar & converter
Ramadan Dates by Year
Calculated start and end dates for every Ramadan period that touches the Gregorian year. These are deterministic planning dates from the tabular Islamic calendar. The locally observed date can differ by about a day because a new Islamic month is established by moon sighting.
Ramadan calendar: 2020β2040
How these dates are calculated
The calculator uses the tabular Islamic calendar, a fixed 30-year arithmetic cycle. It maps 1 RamaαΈΔn in each overlapping Hijri year to a Gregorian date through the Julian Day Number. That makes every calculation reproducible, including the uncommon Gregorian years containing two occurrences.
Observed Islamic dates are not set by arithmetic alone. Weather, location and the authority whose announcement a community follows can move the actual start by a day, occasionally two.