Tibetan calendar

The Tibetan calendar (Tibetan: ལོ་ཐོ, Wylie: lo-tho) 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 (Tibetan: ལོ་གསར་, Wylie: lo-gsar). 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.

There were different traditions of naming years (Tibetan: ལོ་, Wylie: lo) in Tibet. From the 12th century onwards, we observe the usage of two sixty-year cycles. The 60-year cycle is known as the Vṛhaspati cycle and was first introduced into Tibet by an Indian Buddhist by the name of Chandranath and Tsilu Pandit in 1025 CE. The first cycle is the rabjyung (Tibetan: རབ་བྱུང༌།, Wylie: rab byung) cycle. The first year of the first rabjyung cycle started in 1027. This cycle was adopted from India. The second cycle was derived from China and was called Drukchu kor (Tibetan: དྲུག་ཅུ་སྐོར།, Wylie: drug cu skor, Sanskrit Vrhaspati). The first year of the first Drukchu kor cycle started in 1024. The cycles were counted by ordinal numbers, but the years within the cycles were never counted but referred to by special names. The structure of the drukchu kor was as follows: Each year is associated with an animal and an element, similar to the Chinese zodiac. Animals have the following order:

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