Definition:Time/Unit

Definition
The units of measurement of time are universal in all systems of measurement.

The fundamental unit of time is the second, whose symbol is $\mathrm s$.

Derived units of time include:


 * $60$ seconds form a minute, whose symbol is $\mathrm {min}$
 * $60$ minutes form an hour, whose symbol is $\mathrm {hr}$
 * $24$ hours form a day, whose symbol is $\mathrm {day}$.

There are longer time periods, all of which are more or less approximate.