# Second to Hour Converter

## Second

What is the second?

The second is an important unit of time. It is the main unit of time in the SI system of units. It can be defined as the time it takes an electromagnetic field to propagate through 3 x 10 ^{5} km of vacuum.

One solar day has 86,400 seconds. There are 60 second per minute.

Second is not small and specific enough to be used by scientists and engineers so smaller units were derived such as:

- One millisecond which equals 10
^{-3}s. - One microsecond which equals 10
^{-6}s. - One nanosecond which equals 10
^{-9}s. - One picosecond which equals 10
^{-12}s.

## Hour

What is the hour?

The hour is a unit of time. It can be symbolized as hr. It equals 1/24 of a day. It also can be defined as 3600 seconds or 60 minutes.

Time can be measured according to two schemes:

- 24-hour time scheme which starts and ends at midnight.
- Two 12-hr segments per mean solar day ( A.M and P.M).

The first scheme is the most common scheme that is used by engineers and astronomers