24:00:00 -

The most recent international standard for time representation has officially disallowed the use of "24" as an hour, favoring "00:00" to represent the beginning of the day.

Used to mark the very start of a new calendar day. 24:00:00

Many programming languages and digital devices do not allow "24:00:00" as a valid input, automatically defaulting it to "00:00:00" of the next day. 24:00:00