Lunar New Year is the beginning of a new year based on lunar calendars or, informally but more widely, lunisolar calendars. Typically, both types of calendar begin with a new moon but, whilst a lunar calendar year has a fixed number of lunar months, lunisolar calendars have a variable number of lunar months, resetting the count periodically to resynchronise with the solar year. The event is celebrated by numerous cultures in various ways at diverse dates. The determination of the first day of a new lunar or lunisolar year varies by culture.