The Tibetan Calendar is a lunisolar system. The Tibetan year is composed of 12 or 13 lunar months, each beginning and ending with a new moon. A thirteenth month is added approximately every three years; therefore, an average Tibetan year is equal to a solar year. Months are without names, but referred to by their numbers. 

In 7^th century, Princess Wencheng brought the Tang Dynasty’s calendar to Tibet. Later Princess Jincheng (Kyimshang Kongjo) did the same thing. However, after the downfall of the Tubo (Tufan) Dynasty, Tibet became chaotic, and the introduction of the Han Chinese calendars stopped. 

Around 9^th century, Islam expanded into India and many Buddhists escaped to Tibet bringing with them concepts from Indian Astronomy. Tibetans integrated the Indian Astronomy and the Han Chinese calendars to form their own calendars. Later they adopted more from the Han calendars to form the present Tibetan calendars, which started from the year 1027. The Tibetan New Year celebration is called Losar. In 2009, the Tibetan New Year’s Day was on February 25, exactly a month later than the Chinese New Year. 

Each year is associated with an animal sign and an element. This is similar to the Chinese zodiac. The signs alternate in the following order: Rabbit, Dragon, Snake, Horse, Sheep, Monkey, Bird, Dog, Pig, Mouse, Ox, and Tiger. The elements alternate in order: Fire, Earth, Iron, Water, and Wood. 

Each element is associated with two consecutive years, first in its male aspect, then in its female. For example, a male Earth-Dragon Year is followed by a female Earth-Snake Year, then by a male Iron-Horse Year. The gender may be omitted, as it can be inferred from the animal. 

The element and animal designations recur in cycles of 60 years, starting with a (female) Fire-Rabbit year. These big cycles are numbered. The first cycle started in 1027. 

Celestial bodies names are for the days of week, see the followings: 

Notes: Nyi-ma “Sun”, Da-wa “Moon” and Lhag-pa “Mercury” are common personal names for people born on Sunday, Monday or Wednesday respectively.