The Tibetan calendar is a lunisolar calendar, that is, the Tibetan year is composed of either 12 or 13 lunar months, each beginning and ending with a new moon. A thirteenth month is added every two or three years, so that an average Tibetan year is equal to the solar year. The Tibetan New Year celebration is Losar. According to almanacs the year starts with the third Hor month. There were many different traditions in Tibet to fix the beginning of the year.