How to calculate Gengri?

There is an old almanac on the street stall: one every year. As long as 1 yuan.

There are many online, such as Buyiju.

Another one: you can calculate it down: 20 14 July 8, today is Geng Day (indeed), put it aside for ten days, or 18. The 28th is still the same. August 7th (beginning of autumn) or.