— Constant: **internal-time-units-per-second**

Is the integer number of internal time units in a second.

— Function: **get-internal-run-time**

Returns the integer run time in internal time units from an unspecified starting time. The difference of two calls to

`get-internal-run-time`

divided by`internal-time-units-per-second`

will give elapsed run time in seconds.

— Function: **get-internal-real-time**

Returns the integer time in internal time units from an unspecified starting time. The difference of two calls to

`get-internal-real-time`

divided by`internal-time-units-per-second`

will give elapsed real time in seconds.

— Function: **current-time**

Returns the time since 00:00:00 GMT, January 1, 1970, measured in seconds. See current-time.

`current-time`

is used in Time and Date.