Does anybody really care? It's high time you did! And you should also care how time is specified so your documents are second to none, precisely crafted, and, er, processed like clockwork! Benjamin Franklin said, "lost time is never found again." Save editing time with these tips for time treatment from The Chicago Manual of Style.
- Spelled-out forms. Times of day in even, half, and quarter hours are usually spelled out in text. With o'clock, the number is always spelled out.
- My day began at five o'clock in the morning.
- Tennis lessons continued until half past ten.
- We didn't leave the court until quarter of three.
- We resumed play at four thirty.
- Our match finished just before midnight.
- Numerals. Numerals are used (with zeros for even hours) when exact times are emphasized. The abbreviations a.m. (ante meridiem) and p.m. (post meridiem)often appear in small capitals, in which case periods are unnecessary.
- The first serve was hit at 11:22 a.m. and the last point was over at 3:00 p.m.
- He caught the 4:20 p.m. train to Forest Hills.
- Please attend the clubhouse meeting at 10:30 a.m. (EST). Note: in schedules and some publications where space is at a premium, there is a growing practice of using a.m. and p.m. as lower case without periods, as in "2pm" or "4:30am." This practice seems to be growing in informal publications.
- Noon and midnight. Except in the twenty-four-hour system, numerals should never be used to express noon or midnight. Although noon can be expressed as 12:00 m. (m. = meridies), very few use that form. And the terms 12:00 p.m. and 12:00 a.m. are technically invalid. Use noon and midnight instead. In the second example below, note the double date for clarity.
- The Smith-Laver match began at 9:45 a.m. and was over by noon.
- Newcombe was on TV at midnight, August 21-22.
