1,318. Calculating the Head's Position - part 1
Hilchos Kiddush HaChodesh 16:3
If one wants to know the position of the head for any date, one must first calculate the head’s average progress as one does for the average of the sun and the moon. Subtract this number from 360 and the result is the location of the head for that time. The tail is always directly opposite the head.
Hilchos Kiddush HaChodesh 16:4
Let’s say that we wanted to know the location of the head on Friday night, 2 Iyar, of the Rambam’s current year. There are 29 whole days from the night of his starting point until this date. (Continued in halacha 16:5.)