why do months have a different number of days?

Answer 1

Because 28 X 12 doesn't = 365 1/4, duh!!!

Answer 2

I think the 12 month solar calendar was invented before the romans (as some people have suggested).

The ancient egyptians worhiped the sun. They had three seasons, 12 months in a year and 10 days in a week and 3 weeks in a month (exactly 30 days). At the end of the year, they would add the extra five or so days to get to the time for one solar year.

I saw this circular looking calendar painted on the roof of the ancient temple of dendira near Luxor in Egypt (click on first link for picture of it). It was basically a circle with a "god" at each point of the compass (N,S, E,W) and two at intermediate points (NE, NW, SE, SW). That made 12 gods representing the twelve months. They were supporting the circle with 24 hands - hence 24 hours in a day. The ancient egyptians used this to work out when to harvest and plant crops etc and presumably, the romans adopted the same 12 month system and tweaked it a bit after they conquered egypt.

The twelve month calendar works better for the lunar months because it is easy to observe twelve new moons each year. There is a difference in the lunar and solar year because there are about 12 extra days needed to make up every year to synchronise with the solar year (each lunar month is about 29.5 days).

So, twelve new moons in one solar year (that everyone can see), so logical to divide the 365 day solar year into 12 months. The remainder left over then has to be made up with whatever system you use - hence different number of days each month.

Answer 3

why do we have months at all?

it was just an ego thing by powermad kings and emperors, like how we've got greenwich mean time (some king decided that we'd synchronise one cathedral's bells with all the rest - there was no science to it, even cosmology or whatever had nothing to do with it! ...and how we put the clocks back and forth every so often: there's no real reason: the time doesn't change, just how we count it.

So there's a certain number of days in a year, we could have divided them up any way we liked and this is just how it turned out

Answer 4

Thirty times 12 is 360. The year is just over 365 days. So having months with 31 got closer to the 365. Augustus Caesar had a month named after him. He had to have it as long as the one named after Julius, July. So He made it so. February came up short. Nobody liked it anyway.

Answer 5

a year, scientifically, is the time it takes the earth to go around the sun once. this amount of time just doesn't divide up exactly equally to have equal months. So we (well, the romans) did the best we could when we made the calandar to make it as even as possible so there wouldnt be one month at the end of the year with only 10 days or something.

Answer 6

because of the fact the kind of days isn't precisely 365 each and each 12 months... it s 365.25 days a 12 months... there is one greater day each and every 4 years because of the fact earth doesnt rotate the sunlight at precisely twelve months... so february have only 28 days

Answer 7

Because you can't split a year into 12 equal slices and you need a bit of scope for those pesky leap years.

Answer 8

because some roman bloke couldn't spilt 365 equally. remember no calculator in them times

Answer 9

the ancient calendar is from Greece, and their months differed

Answer 10

It's because of the movement of the sun.

Answer 11

I'd really have to ask Augustus ... or was it Julius, who made this calender?

Dang, forgot they're all dead by now.

Sorry, buddy, can't help you there.