Making sense of Bangladeshi holidays is complicated by the fact that four different calendars combine to make up Bangladeshi holidays: the Gregorian, Islamic, Hindu and Buddhist calendars all contribute a few holidays each. The Islamic calendar is ten days shorter than the Gregorian calendar, and hence, Muslim holidays begin ten days earlier every year. The Hindu calendar is a lunar calendar and so the holidays stay around the same period each year. There is only one Buddhist holiday in May so thankfully that one is less complicated. Finally, the Gregorian calendar holidays are at the same time every year. Unless otherwise indicated, the religious holidays below are public holidays in which you can expect most government offices and shops to be closed.