I have always felt that the 31-30-31-30-31 pattern from March through July, Repeating August through December, and then starting again in January was significan

I have always felt that the 31-30-31-30-31 pattern from March through July, Repeating August through December, and then starting again in January was significant. I once wrote an extremely short assembly language routine (PDP-11 I think) for calculating the ordinal date from the calendar date that used simple integer arithmetic (multiply by 153 and divide by 5, I think) to calculate the days in the whole months starting in March. 30.6 rounds to 31 61.2 rounds to 61 91.8 rounds to 92 122.4 rounds to 122 153.0 rounds to 153 etc. See http://www.cs.utsa.edu/~cs1063/projects/Spring2011/Project1/jdn-explanation.html http://www.cs.utsa.edu/~cs1063/projects/Spring2011/Project1/...