What is the exact time of a day? I think that is a little bit less that 24 hours right?

Question

I need to know please

Answer 1

For the Earth to rotate & be *exactly* back to the same position, it's 23 hours and 56.2 minutes.

For the *sun* to be *exactly* over the same spot, it's 24 hours.

The reason is, as the Earth orbits, it needs to rotate just a *little* bit more to get the sun back over the same meridian.  But for something fixed in space (like a far-off star), the Earth always rotates the same amount, and it's about 4 minutes less for 1 exact rotation than a solar day.

Answer 2

It is 23.934 hours. but if you round off the last figures, it becomes 24 hours. There are 86400 seconds in a day.

Answer 3

yep, but the days are gradually getting longer because the earth is not spinning as fast as it used to. of course this is something like gaining 2 seconds every 25 million years

Answer 4

First couple of answers were mostly right. The sidereal rotation period (generally considered the "true" rotation period) of Earth is 23 hours, 56 minutes, and about 4.1 seconds. It is getting longer at an extremely slow pace.

However, despite what you learned in school, Earth's rotation is not exactly what we use to measure a day. A day is the amount of time between subsequent crossings of the sun at a specific meridian from a fixed point on Earth's surface. That's fancy talk for how long it takes the sun to return to the same spot in the sky. How long that takes varies throughout the year because it depends on how quickly the Earth is moving in it's orbit (which changes). On average though, it is 24 hours, which is what we define a day to be.

In truth, it's more like 24 hours and 2 milliseconds, because the slowing of Earth's rotation has caused the length of the day to increase since we defined it specifically decades ago. A couple milliseconds isn't much, but after 500 days, that extra 2 milliseconds turns into our clocks falling 1 second behind, which is why we have leap seconds. It doesn't happen precisely every 500 days because small things like the motions of the Earth's crust etc affect it.

Answer 5

Ah, I just learned this in science class. One day is exactly:

23 hours, 56 minutes,  and 4.01 seconds. (according to my teacher)

I don't have the greatest memory, so this was taken from my notes.

Have a nice day!

Answer 6

As the best I can describe a day is exactly 23.934 solar hours on Earth.  

Answer 7

Yes, it is actually about 23 hours and 56 minutes.  That is how long it takes for the Earth to make one complete rotation about it's axis.  The 24 hour day comes from the fact that it takes the extra 4 minutes for the Sun to return to the same meridional position in the sky.  That is because the movement of the Earth in it's orbit causes the Sun to shift eastward in the sky.