Chapter 59 Chapter 16 Different Calendars of Ethnic Minorities

Tibet imported the Kalachakra calendar from India in the 11th century. After 200 years, many books introducing the Kalachakra calendar came out one after another.At the same time, the Tibetan people also absorbed the Han people's lunar calendar method, the twenty-four solar terms and the solar and lunar eclipse calculation method of the Han people.In general, the Tibetan calendar system combines the features of the Hindu and Han calendars (see Figure 23). The Tibetan calendar uses the year when the Kalachakra calendar was introduced, that is, 1027 AD, as the calendar year. The five elements replace the heavenly stems, and the twelve zodiac signs replace the earthly branches.The Tibetan calendar is a lunisolar calendar, the average year length is close to the tropical year, and the average month length is close to the synodic month.

The Tibetan calendar has a unique concept of missing days and heavy days.The so-called "missing day" means that yesterday's date directly jumps to tomorrow's date.The so-called "heavy day" means using the same date for two consecutive days.The 1st, 15th, and 30th of each month in the Tibetan calendar cannot be missed, and the 1st and 15th must coincide with the new moon and the new moon. Therefore, the arrangements for missing and double days in the Tibetan calendar are mainly based on the actual measurement of the new moon.At the same time, it shows that although every month in the Tibetan calendar has a 30th day, not every month has 30 days.In short, try to keep the average number of days in the month close to the synodic month.

In 1916 AD, Tibet set up a special department for the compilation of almanacs, called the Calendar and Almanac Bureau.It is calculated every 10 years and lasts for one and a half months.The almanac is printed and distributed by the local government every year. There are two printed editions, one for officials and one for ordinary Tibetans.