Scientific knowledge of the calendar
1. Types of calendars:
① Gregorian calendar: Based on the period of the earth’s revolution around the sun.
②Lunar calendar: Based on the cycle of moon phases.
③Lunar-solar calendar: Combining the earth’s revolution cycle around the sun and the moon phase change cycle.
2. my country’s calendar consists of the Gregorian calendar and the lunar calendar. The Gregorian calendar (including year, month, day, and week) belongs to the solar calendar, the lunar calendar (including the year, month, day, and solar terms) belongs to the lunar calendar, the months in the lunar calendar belong to the lunar calendar, and the twenty-four solar terms in the lunar calendar belong to the solar calendar.
3. Leap year: A leap year that can be divisible by 4 in AD, and a leap year in a century that can be divisible by 400. The Gregorian calendar has 365 days in a normal year and 366 days in a leap year (97 of the 400 years are leap years and 303 are a normal year) in February 28 days in a normal year, and 29 days in February in a leap year.
4. Twenty-four solar terms: In ancient my country, the cycle of the four seasons was divided into twenty-four segments. Each segment (approximately 15 days) is called a solar term, which belongs to the solar calendar and has a guiding and predicting role in people’s production and life.
The origin of the calendar
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 opened 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 calendar, lunar calendar, and Gandhi calendar.