Why a day has 24 hours?

Question

I understand that a year has 365/366 days due to the time earth go around the sun. And that 365 is divide by 28, the time moon goes around the earth, to have 12 months. Some months are added to have more than 28 days (so that to have the total 365 days a year) - they add it due to the importance of the months.

Now my question goes to the unit: the day. Why are there 24 hours a day everyone?

Answer 1

like socrates66 says, it takes approximately 23 hours and 56 minutes for the earth to rotate 360 degrees on its axis.  These minutes do add up and every 4 years it gives us an extra day, which is why we have leap years.  

Answer 2

In case you're asking why has the day been divided into 24 hours exactly:

In ancient civilisations, time between the sunrise and sunset was divided into 12 parts, most likely after the number of lunar cycles in a year. Thus, the whole cycle of day and night contains 24 hours.

Hope that helps.

Answer 3

Because it takes 24 hours for the earth to rotate thats why we have day and night

Answer 4

I think it goes back to the babylonians or sumerians, or one of those early civilizations, the same one that gave us 60 minutes and 60 seconds, and 360 degrees in a circle (used a 60 based counting system rather than a 10 based counting system).  Daylight time was divided into 12 pieces, and it stuck.  24 hours came about when people assigned another equal amount of 12 hours for the night.

Not sure why 12 was chosen for dividing day, but 12 is easily split into 6,4,3,and 2, which made it easier to split the day up into smaller parts for different tasks (rather than 10, which only easily goes 2 and 5).

Answer 5

The earths rotation on its axis causes "noon" to "noon" to occur every 24 hours.  In relation to the sun, a "day" on earth is exactly 24 hours.  (We rotate 15 degrees every hour.  15 X 24 = 360, the number of degrees in a circle (or in this case, on a sphere)).  

The 23 hours 56 minutes figure you might hear about is the earth's rotational period in relation to the stars.  The earth has moved approximately 1/365 of its orbit during this period, meaning the sun, in relation to the stars in our sky moves about 4 minutes each day.  There is no rounding involved in the 24 hours in a day.  It is exact.

Answer 6

because thats how long it takes for the earth to spin round 360 degrees on its axis.  

Answer 7

because it takes about 23 hours 56minutes for the earth to make a full rotation. so, we round off to 24 hours. that is why the time of daylight changes day by day.

Answer 8

that's how long it takes for the sun to go allllllll the way around the earth. also, it's actually more than just 24 thats why we have leap years.

Answer 9

I have no idea but all we should think about is make the best of every day