Public holidays in Bhutan consist of both national holidays and local festivals or tshechus. While national holidays are observed throughout Bhutan, tsechus are only observed in their areas. Bhutan uses its own calendar, a variant of the lunisolar Tibetan calendar. Because it is a lunisolar calendar, dates of some national holidays and most tshechus change from year to year. For example, the new year, Losar, generally falls between February and March.