Ante meridiem (a.m) / Post meridiem (p.m.) - Washington Post (7/12/1991)

(...) Every week I find myself befuddled by your paper's insistence on erroneously listing late-night movie times in TV Week. Certainly the good people at your paper know that the Earth makes one revolution every 23 hours and 56 seconds, although that number is rounded off to an even 24 hours, and that a 24-hour period is divided into 12 hours ante meridiem (a.m.) and 12 hours post meridiem (p.m.). The a.m. hours are from midnight until noon; p.m. hours are from noon until midnight. (...)

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