Does anyone know how to write js's lunar calendar algorithm?

Actually, I don't understand this algorithm either. I posted it on the internet. I don't think we need to delve into this formula. Anyway, there are ready-made codes:

Suppose: the number of AD years-1977 (or1901) = 4q+r.

Then: Lunar date =14q+10.6 (r+1)+date ordinal of the year-29.5n.

(Note: in the formula, q, r and n are all natural numbers, r

For example: Lunar date1May 7, 994 is:

1994- 1977= 17=4×4+ 1

So q = 4, r = 1, so the seventh day of the fifth lunar month is:

14×4+ 10.6( 1+ 1)+(3 1+28+3 1+30+7)-29.5n

= 204.2-29.5 Newton

Then divide 204.2 by 29.5 to get the quotient 6...27.2, where 6 is the value of n and the remainder 27 is the 27th day of the lunar calendar.