如何在时间time上减几小时

RelativeTime PowerScript function
Description

Obtains a time that occurs a specified number of seconds after or before another time within a 24-hour period.

Syntax

RelativeTime ( time, n )

Argument Description
time A value of type time
n A long number of seconds
Return value

Time. Returns the time that occurs n seconds after time if n is greater than 0. Returns the time that occurs n seconds before time if n is less than 0. The maximum return value is 23:59:59. If any argument's value is NULL, RelativeTime returns NULL.

This statement returns 19:01:41:

RelativeTime(19:01:31, 10)

This statement returns 19:01:21:

RelativeTime(19:01:31, - 10)