How is it that we got the notion that a day is only 24 hours?

um ok you waterhead, it takes almost 24 hours for the earth to complete rotation, because it is not quite 24 hours we have a "leap year"

Actually daylight savings time has nothing to do with any of that. It is actually up to each state if they want to do it or not. Like Arizona - they don't do it... And I think there is another state but I can't remember who it is... But anyway, I think they came up with it because of the sun and moon falling and I agree - I think it was mathmatical.

12 months, 4 seasons... are you getting it now ?

We can thank the ancient Egyptians for that. They discovered that star patterns emerged over the horizon in hour-long intervals, and were able to divide the night into 12 hours. To match, they divided the day into 12 hours as well. Since they were near the equator, the days and nights were equal length.

It has to do with the earth's rotation. They came up with it mathmatically, and i don't know enough about it to explain exactly how. However, the time is not exact- hence daylight savings time.

You know what...here's my guess. If you all remeber the shadow clock. They had to split the plate into hours...well...how do you cut the pie? in half, then again, again, and one more time in half...you get 12 IT'S BEAUTIFUL!!!!!!!!!! p.s.- rate me please!

hmmmm....that is an good question!!!

The numeric system that ancient Babylonians used was a sexagesimal (60 based) system. The division of minutes and seconds are still based on 60 a year has 12 months one fifth of 60, each corresponding a zodiac sign. The earth rotates around its access every 23.934 hours. I think the only reason hours and minutes are divided in 60 instead of an easier number such as 100 is the fact that all the clocks in the world are set that way. There really isn’t a good scientific reason why there should be 24 hours in a day. A day divided in 100 units would work much better especially when it comes to measuring time and calculating based on time using a calculator or a computer. Now that we can measure time to a fraction of a second, we measure it in 10th or 100th and so on of a second not 1/60th of a second.