Why do different months have different number of days?

Question

Why does February just have 28 days...why not 30?

Answer 1

Originally they didn't have different numbers. But then the Romans started mucking about with the calendar to make their months longer than others. July (after Julius Caesar) and August (after Augustus Caesar) were lengthened - at the expense of February. The days were borrowed from February - and never returned.

But then, the Julian calendar wasn't that accurate anyway. Had to be replaced by the Gregorian calendar. But by the time of the Pope Gregor who introduced that calendar, the damage had been done. That's why the Winter Solstice is on the 21st instead of being New Year's Day as was originally the case. The calendar had drifted that far.

Answer 2

Since a year is defined as 365 days, you can't divide it to have to same number of days in each of the 12 months. That's why some have 31, some 30, and February has 28.

Answer 3

because the number of days is not exactly 365 each year... it s 365.25 days a year... there's an additional day every four years because earth doesnt rotate the sun at exactly 365 days... so february have just 28 days

Answer 4

This is to even out the calender. The 365 days we have each year equals the earth making one full revolution around the sun. This is why we have leapyear every four years. If February was say, 30 days long, the calender year would lose its sync.