Did you ever wonder why December has 31 days? (1997)

And it's wrong. The email is from 1997, but now you can look it up on wikipedia: http://en.wikipedia.org/wiki/Julian_calendar

Short version - Julius didn't name the month after himself, the roman Senate did. There's good indications that July and August had 31 days before the reform, and February has less days because it was the last month of the year.

For centuries in the western world, the Christian church, which considered this to be in its purview, kept trying different calendar schemes to try to make a set of months, preferably equal, fit neatly into the year.

There have been may solutions tried or proposed, and the history of this has a certain puzzle-like fascination, but it's not clear to me why people cared so much about this. Astronomical periods are OK, apparently, for years and days, yet weeks and calendar months are arbitrarily imposed.

Make your hand into a fist

Starting at the left, each knuckle and the space in between counts as one month.

Count all the way across and when you get to the end of your fist, start over (or carry over to the next fist)

Knuckle months have 31 days, months in between knuckles have 30 days (except for February)

I thought it was because of the knuckles.

But if you want to discuss Romans and calendars, you've got to mention that Mars was there first month (because it's such a great month to start a fresh military campaign). So February was the last, and got whatever remains.

Why July and August both have 31 days, I have no idea. Augustus' jealousy sounds plausible, but apparently it's not true. So what's the real reason for this?

It's my understanding that the original basis for months was the lunar cycle, which is astronomical for common definitions of the word. Part of what makes picking a calendar difficult is that the ~29.5 day lunar month doesn't fit neatly into the ~365.25 day solar year. So we've ended up with succession of adjustments and fudge factors.