Calendar question - why does Feb have 28 days?

I understand 365 is not evenly divisible by 12. You get 30 with a remainder of 5.

Simple enough. Randomly pick 5 months and make them 31 days. You get a total of 365. Add 1 to a month for leap years.

But, that’s not what happened. They added 1 extra day to seven months. giving 367. So they had to steal 2 days from Feb. to get 365.

What was the reason for this unusual math?

Also, what was the logic for adding the extra day to Jan,March,May,July,Aug,Oct,Dec. Forcing everyone to memorize a poem to keep it straight?

See:

http://en.wikipedia.org/wiki/Roman_calendar.

Briefly even number of days was considered unlucky so months had 29 or 31 days, but they needed one even number of days month and February got unlucky. Then they began messing with it more.

The Master Speaks!

Cecil covered the question thoroughly. Now I know. thanks. :wink:

Personally I’m fond of the thirteen month calendar of 4 exact weeks each with only 1 day left over as a convenient holiday…

The 13th month always has the worst weather though…

there’s no need to memorise the poem. look at the knuckles on your fist excluding your thumb’s. four knuckles three indents. start with the knuckle on your index finger and count, going back to it when you reach the end.

JAN feb MAR apr MAY jun JUL
AUG sep OCT nov DEC

I learned a slightly more dramatic variant of that: Instead of counting on the knuckles and gaps between them, count on the fingertips (thumbs excluded) and in between the knuckles.

(But if you’re all thumbs, sucks to be you. :slight_smile:

I hadn’t heard the knuckle technique before. That is easier to remember than the calendar poem.

As long as you can remember which have 30 and which have 31.

I guess the short months go with February.

I have to ask - if you don’t think this technique tells you which months have 30 days, what do you think it is for?