(32SII) Day Number of the Year

[Eddie W. Shore]

This formula calculates the day number of any date (given month and day). A 365 day year is used. If you are operating with a leap year with dates after February 28, add 1.

Hence in non-leap years, January 1 is Day 1, February 1 is Day 32, etc..., December 1 is 335, and December 31 is 365.

Details are at my blog: http://edspi31415.blogspot.com/2014/01/h...-year.html

Formula:

Day Number, 365 Day Year, M≤2:
D + IP(30.6M + 1.6 + 367.2) - (34 + 365) = D + IP(30.6M + 368.8) - 399

M>2:
D + IP(30.6M + 1.6) - 34

Here it is in RPN format. I broke up some of the larger numbers into an addition of two smaller ones and used flags to keep the program within one label.

HP 32SII:

Code:


N01 LBL N
N02 CF 0 \\clear flag 0 (any user flag will do)
N03 INPUT M
N04 2
N05 x≥y?
N06 SF 0 \\set flag 0
N07 R-down \\bring M to the X stack
N08 30.6
N09 × 
N10 1.6
N11 +
N12 FS? 0
N13 367.2
N14 FS? 0
N15 +
N16 IP
N17 INPUT D
N18 +
N19 34
N20 -
N21 FS? 0
N22 365
N23 FS? 0
N24 -
N25 CF 0
N26 RTN