Calculation rules of Gregorian calendar

There are several upstairs. Do not mislead the landlord.

The Gregorian calendar is based on the way of nature, so twelve hours are divided according to the sun, not according to Beijing time.

For example, you can't say that the sunrise from 3: 00 to 5: 00 is Shi Mao, because in some places, the sun doesn't rise between 3: 00 and 5: 00.

Therefore, it must be based on local time. Remember, remember.