|Definition:|| quantitative expression marking an instant within a calendar day by the duration elapsed after midnight in the local standard time|
NOTE 1 Usually, clock time is represented by the number of hours elapsed after midnight, the number of minutes elapsed after the last full hour, and, if necessary, the number of seconds elapsed after the last full minute, possibly with decimal parts of a second. Examples of the standardized representation are 09:01; 09:01:12; 09:01:12,23. The combination of calendar date and clock time is denoted by inserting T; an example is 1998-11-15T09:01:12. (See ISO 8601).
NOTE 2 The duration used in the definition is modified for special situations (daylight saving time, leap second).