Leap year This makes it easy to convert dates to or from Gregorian. The Thai solar calendar uses the Buddhist Era (BE), but has been synchronized with the Gregorian since AD 1941. From AD 8 the Julian calendar received an extra day added to February in years that are multiples of 4. The Coptic calendar and Ethiopian calendar also add an extra day to the end of the year once every four years before a Julian 29-day February. This rule gives an average year length of 365.25 days. However, it is 11 minutes longer than a tropical year. This means that the
Kurdish calendar by a leap year every fourth year. It starts with the exact first day of spring according to the Gregorian calendar (March 20 or 21). Like the Gregorian system, the Kurdish calendar divides the year into four seasons: Buhar, Tawistan or Hawín, Payiz and Zimistan. It divides the year into 12 months, each month into four weeks and every week into seven days. In the Kurdish calendar the first six months (comprising spring and summer) are each 31 days long, while the next five months (in fall and winter) are 30 days each. The last winter month, the 12th month