12-hour Clock

The 12-hour clock is a time convention in which the 24 hours of the day are divided into two periods: a.m. (from the Latin ante meridiem, meaning "before midday") and p.m. (post meridiem, "after midday"). Each period consists of 12 hours numbered: 12 (acting as zero), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

The 12-hour clock was developed over time from the mid-second millennium BC to the 16th century AD.

Read more about 12-hour Clock:  History and Use, Abbreviations, Confusion At Noon and Midnight

Famous quotes containing the word clock:

    We are hardly ever grateful for a fine clock or watch when it goes right, and we pay attention to it only when it falters, for then we are caught by surprise. It ought to be the other way about.
    Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)