Page 56 - Perfect English Grammar: The Indispensable Guide to Excellent Writing and Speaking

contractions (see section 4.5), an apostrophe shows where letters—or, in this
case, numbers—have been dropped.

■ ■ the ’60s the 60s Microsoft Word, the most widely used word processing

software in the world, has for more than 30 years mistakenly autocorrected

apostrophes at the beginning of words, including date abbreviations. The
apostrophe should curve to the left, not the right.

■ ■ Wrong: the ‘80s Right: the ’80s

4.8.3 TIME AND THE CLOCK

In North American English we use a.m. (ante meridiem, meaning “before

midday”) for the hours of the day between midnight (12 a.m.) and noon (12
p.m.), and p.m. (post meridiem, meaning “after midday”) for the hours between

noon and midnight. The abbreviations can be written several ways, varying
capitalization, punctuation, and spacing. As always when you have choices, try

to find out what your boss or teacher prefers and stick to it.

■ ■ 2 A.M.—2 a.m.—2 am—2am 5:30 P.M.—5:30 p.m.—5:30 pm—

5:30pm Note that in Europe and other parts of the world, it is common to
use a 24-hour clock (what people in the United States tend to think of as

military time). With a 24-hour clock, the hours don’t start over after noon but
continue increasing until resetting to zero at midnight.

■ 12:00 a.m. = “midnight” = 00:00
■ 1:00 a.m. = 0100 = “oh one hundred hours” = “one in the morning”

■ 7:10 a.m. = 7:10 = 0710 = “seven ten” = “seven ten in the morning”
■ 12:00 p.m. = “noon” = 12:00

■ 1:00 p.m. = 13:00 = 1300 = “thirteen hundred hours” = “one in the
afternoon”

■ 6:20 p.m. = 18:20 = 1820 = “eighteen twenty” = “six twenty at night”