the 24-hour clock is a way of expressing time. to distinguish it from the 12-hour clock.

in the 24-hour clock, 1 p.m. is written as 13 p.m. 2pm, was written 14pm.

although, in life, we mostly use the 12-hour clock. for example, let's say we get off work at 5 p.m.

what we say, "9 to 5" refers to 9 a.m. and 5 p.m. (the time when ordinary employees go to and from get off work).

however, in scientific and rigorous explanations, in contracts and other legal documents, time must be written in 24-hour format.

the twelve-hour clock is a time rule that divides the 24 hours of a day into two periods, namely morning (am, latin ante meridiem means before noon) and afternoon (pm, latin post meridiem means after noon). each period consists of twelve hours, represented by the numbers 12, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 in order. the morning session runs from midnight to noon, while the afternoon session runs from noon to midnight.