How to calculate the entry time and exit time?

Incubation time: the third Geng day after long summer.

Emergence time: the first Geng day after beginning of autumn.

The calculation method of ambush is more complicated. If you want to know the date of the ambush, you must first be familiar with China's unique "dry branch method". The time of accommodation is not fixed every year, and the length of accommodation is also different. You need to consult the almanac to calculate.

We can simply use the formula of "Xia San Geng" to express the lodging date, that is, from the third Geng day in Xia Hou, the first lodging within 20 days is 10 day, the middle lodging is 10 day or the last lodging is 10 day.

Reference voltage calculation formula:

A new algorithm in 265438+20th century —— Gengri formula: GR=(D-[Y/4])MOD 10(GR Gengri, d even years 1 odd years 6, y years, [] rounding, MOD rounding).

Initial GR plus 1 0 (except in 2084), intermediate GR plus 20, and final GR minus 1 when it is greater than 7, plus 9 when it is less than 8 (except1minus1in 996).

For example, in 2006, GR = (1-[6/4]) mod10 = 0 (10), with the first stay on July 20th, the last stay on August 9th.