How to calculate which year is a year (record the year with heaven and earth)?

1, annual stem formula: annual stem = annual single digits -3 (applicable to any year, single digits are less than or equal to 3, borrow 10).

Take 20 19 as an example, its single digit is 9,9-3 = 6, which means that the heavenly stems are their own.

2. Annual expenditure formula: annual expenditure = (year +7) ÷ remainder 12 (divisible by remainder 0, that is, remainder 12= ugly).

Taking 20 19 as an example, the remainder of (20 19+7)÷ 12 is 10, that is, the ground branch is Hai.

Extended data:

The cycle of heavenly stems is ten, with ten hours, ten days, ten months and ten years as different cycles, which are repeated in an orderly manner and form a stable periodic law. The cycle of the underground branch is twelve, with twelve hours, twelve days, twelve months and twelve years as different cycles, which are repeated in an orderly manner and form a stable periodic law.

With the cooperation of heavenly stems and earthly branches, we created a cycle of 60 hours, 60 days, 60 months and 60 years, which was repeated in an orderly manner and formed a stable periodic law. Because the cycle of cooperation between stem and branch begins with heavenly stem "A" and earthly branch "Zi", people call this cycle with 60 as a process "Jia Zi".

Baidu Encyclopedia-heavenly stems and earthly branches