From ancient times to the present, there are three ways of saying the calendar:
1. Almanac and the like.
2. Today refers to the book with the year, month, day, week, solar terms, anniversary, etc., one book per year, one page per day, and to be removed day by day. Some are hung on the wall, and some are placed on the table.
3. The historian records the government affairs of the country according to the day, which is the basis for the historian to compile the history of the country.
The real calendar came into being, and the imperial calendar was already used in the imperial palace in the first year of Yongzheng Emperor Shunzong of Tang 1100 years ago. One page in the first day records the state, court events, and the emperor’s words and deeds. The imperial calendar is divided into twelve volumes. The number of pages in each volume is the same as the number of days in a month, and each page is marked with the number of days and dates.
Nowadays, common calendars, whether in paper publications, mobile phone applications, or electronic desk calendars, usually contain three calendars: Gregorian, Lunar and Ganzhi calendars.