Approximately how many days shorter is the lunar Islamic (Hijri) year compared to the solar Gregorian year?

Explanation

– The lunar Islamic (Hijri) year is approximately 11 days shorter than the solar Gregorian year, since it is based strictly on the cycles of the moon rather than the earth’s orbit around the sun.
– This difference causes Islamic months, including Ramadan and the Hajj season, to gradually shift earlier each year relative to the fixed Gregorian calendar.
– For exams, note that this shift means Islamic lunar months complete a full cycle through all four seasons approximately every 33 years.