I have a mathematical and programming background. Calculations involving calendar dates is a royal PITA!
February is particularly bad because the (1) it has a variable length because of leap years and (2) it is shorter in length than all other months. If there is to be a "leap day," it should be at the end of the year, not someplace in the middle. My best suggestion that I have would be to keep a 12 month calendar, but have the number of days have the sequence: 30 31 30 31 30 31 30 31 30 31 30 (30+), where the last month (named December?) would normally have 30 days, but in a Leap year it would be 31. The "business" quarters would usually be 91 days in length, but would have 92 days in the second quarter, and on leap year, the fourth quarter. I suspect that I am far from the first one to make this proposal.
The number of days in a month would be considerably easier to calculate with the odd numbered months (if we call the first month 1) having 30 days, and the even numbered months having 31 days, except that we subtract 1 day from month 12 if it is not a leap year.
220.127.116.11 17:49, March 1, 2015 (UTC) Robert L. Smith email@example.com