# How Many Seconds Are in a Day ?

**There are 86,400 seconds in a day.** This calculation is based on the conventional definition of the length of a day; for convenience, a day is defined as 24 hours.

A day is considered to be the amount of time it takes the earth to rotate once around its axis. This rotation takes 23 hours, 56 minutes and 4.1 seconds, which is exactly 86,164.1 seconds long.

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