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: loin Tibet. From the 12th century onwards, we observe the usage of two sixty-year cycles. The 60-year cycle is known as the Bṛhaspati (or Vṛhaspati) cycle and was first introduced into Tibet by an Indian Buddhist by the name of Chandra Nath and Chilu Pandit of Tibet in 1025 CE. The first cycle is the rabqung (Tibetan: རབ་བྱུང༌།, Wylie: rab-byung) cycle. The first year of the first rabqung cycle started in 1027. This cycle was adopted from India. The second cycle was derived from China and was called zhugju gor (Tibetan: དྲུག་ཅུ་སྐོར།, Wylie: drug-cu skor). The first year of the first zhugju gor 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 zhugju gor was as follows:

The Tibetan people (Tibetan: བོད་པ།་, Wylie: Bodpa; Chinese: 藏族; pinyin: Zàng Zú) are an ethnic group that is native to Tibet, which is mostly in the People's Republic of China. They number 5.4 million and are the 10th largest ethnic group in the country. Significant Tibetan minorities also live in India, Nepal, and Bhutan. The Khampas of Tibet are originally from Mongolia.

Tibetans speak the Tibetan language, which belongs to the Sino-Tibetan languages and has many mutually unintelligible dialects. The traditional, or mythological, explanation of the Tibetan people's origin is that they are the descendants of the monkey Pha Trelgen Changchup Sempa and rock ogress Ma Drag Sinmo. Most Tibetans practice Tibetan Buddhism, though some observe the indigenous Bön and others are Muslims. Tibetan Buddhism influences Tibetan art, drama, and architecture, while the harsh geography of Tibet has produced an adaptive culture of Tibetan medicine and cuisine.

As of 2008, there are 5.4 million Tibetans in China. The SIL Ethnologue in 2009 documents an additional 189,000 Tibetan language speakers living in India, 5,280 in Nepal, and 4,800 in Bhutan. The Central Tibetan Administration's (CTA) own refugee register counts 145,150 Tibetans outside Tibet: a little over 100,000 in India; in Nepal there are over 16,000; over 1,800 in Bhutan and more than 25,000 in other parts of the world. There are Tibetan communities in the Australia, Canada, Costa Rica, France, Mexico, Norway, Taiwan, Switzerland, United Kingdom, and USA.^{[citation needed]}