1,313. Why We're Doing This

Hilchos Kiddush HaChodesh 15:2

Remember, the reason we’re going through all the calculations discussed over the past few chapters is to be able to determine when the moon will be visible. The double distance (from halacha 15:1) cannot be smaller than five degrees or greater than 62 degrees on the night when the moon is seen. It will never exceed these limits.

Hilchos Kiddush HaChodesh 15:3

We must therefore consider the double distance. If it is five degrees - or close to it - then there is no reason to worry about an increase, so this measure need not be increased. If the double distance is between six and 11 degrees, add one degree to the average of the moon in its path. If the double distance is between 12 and 18 degrees, add two degrees to the average of the moon in its path; if it’s between 19 and 24 degrees, add three degrees the average; from 25 to 31 degrees, add four degrees to the average; from 32 to 38 degrees, add five degrees to the average; from 39 to 45 degrees, add six degrees to the average; from 46 to 51 degrees, add seven degrees to the average; from 52 to 59 degrees, add eight degrees to the average; from 60 to 63 degrees, add nine degrees to the average of the moon in its path. The average of the moon in its path after making any necessary addition is called the proper course.