Tibetan medicine and Tibetan calendar are calculated by Tibetan astronomical calendar.

In Tibet, Tibetan medicine and Tibetan calendar are closely linked. In the 8th century A.D., the Four Medical Codes written by the Tibetan medical scientist Yuto Ma Ning Yuan Dangombo came out, forming a relatively complete theoretical system of Tibetan medicine. Because Tibetan doctors believe that with the change of seasons, the qi and blood circulation of the five internal organs of the human body is also different, so Tibetan doctors attach great importance to observing the changes of stars, clouds, winds, lakes and birds.

According to Tibetan customs, the astronomical calendar business is located in Tibetan hospitals. There are a group of scholars in Tibetan medical colleges. The annual calendar of each year was calculated by scholars of Tibetan Medical College in the previous year.

The official use of Tibetan calendar began in A.D. 1027, and has been popular ever since. It turns out that in the first century BC, Tibetans had their own calendar algorithm, that is, the full moon, the missing moon, the new moon and the full moon were used to calculate the calendar of Bonism. New Year's Day at that time was equivalent to the current Tibetan calendar 1 1 month 1 day. There is an ancient calendar book named "textile old man's monthly calculation", which summarizes in detail the rich production experience and astronomical calendar knowledge of Tibetan people at that time. Later, Princess Wencheng entered Tibet and brought many classics, among which the astronomical almanac played an important role in perfecting and developing the original Tibetan calendar. At this time, the determination of New Year's date has progressed from the brightness of the moon to the stars as the main basis, that is, the brightness and position of ghost stars as the standard. However, the New Year is still on 1 1 month 1 day in the Tibetan calendar. Later, the original Tibetan calendar absorbed the calendar calculation technology of the Han nationality and gradually improved into today's Tibetan calendar.

The Tibetan calendar stipulates that a year is 12 months, with 30 days for the big month and 29 days for the small month. Every thousand days or so, there is a leap month to adjust the relationship between months and seasons. The Tibetan calendar adopts the chronological method of the time wheel system, and divides celestial bodies into twelve constellations, namely, Aries, Pisces, Taurus, Capricorn, Gemini, Lion, Cancer, Aquarius, Sagittarius, Virgo, Scorpio and Libra. Match the zodiac with the chronology of the five elements. Taking 12 years as a small cycle and 60 years as a big cycle is called a "round" (that is, a round). The first "Rao Tong" began in A.D. 1027. 1987 is the first year of 17 "detour". The Tibetan calendar of 199 1 is called the Year of the Golden Sheep. This is similar to the chronology of the China lunar calendar, and the genus is the same.

The Tibetan calendar not only predicts whether there will be good weather, drought, snowstorm or earthquake in the coming year, but also indicates good or bad luck every day when it rains. It is said that Naqu Tibetan Hospital predicted three earthquakes in northern Tibet during 1986, and the approximate time and orientation were very accurate. Mainly based on astronomical forecasts. The astronomical phenomena are in the shape of a giant Buddha. The giant Buddha symbolizes the earth, and its posture is symbolic. If the giant Buddha does not stand, it means earthquakes, hurricanes and plagues. When the Buddha is seated, there will be peace on earth.