b. Clock time (see also Time):
- 4:30 p.m.; half past 4
- 10 o'clock or 10 p.m. (not 10 o'clock p.m.; 2 p.m. in the afternoon; 10:00 p.m.)
- 12 p.m. (12 noon)
- 12 a.m. (12 midnight)
- 4ʰ30ᵐ or 4.5ʰ in scientific work, if so written in copy
- 0025, 2359 (astronomical and military time)
- 08:31:04 (stopwatch reading)
c. Dates:
- 9/11 (referring to the attack on the United States that occurred on September 11,2001)
- June 1985 (not June, 1985); June 29, 1985 (not June 29th, 1985)
- March 6 to April 15, 1990 (not March 6, 1990, to April 15, 1990)
- May, June, and July 1965 (but June and July 1965)
- 15 April 1951; 15-17 April 1951 (military)
- 4th of July (but Fourth of July, meaning the holiday)
- the 1st [day] of the month (but the last of April or the first [part] of May, not referring to specific days)
- in the year 2000 (not 2,000)
In referring to a fiscal year, consecutive years, or a continuous period of 2 years or more, when contracted, the forms 1900–11, 1906–38, 1931–32, 1801–2, 1875–79 are used (but upon change of century, 1895–1914 and to avoid multiple ciphers together, 2000–2001). For two or more separate years not representing a continuous period, a comma is used instead of a dash (1875, 1879); if the word from precedes the year or the word inclusive follows it, the second year is not shortened and the word to is used in lieu of the dash (from 1933 to 1936; 1935 to 1936, inclusive).
In dates, A.D. precedes the year (A.D. 937); B.C. follows the year (254 B.C.); C.E. and B.C.E. follow the year.
d. Decimals: In text a cipher should be supplied before a decimal point if there is no whole unit, and ciphers should be omitted after a decimal point unless they indicate exact measurement.
- 0.25 inch; 1.25 inches
- silver 0.900 fine
- specific gravity 0.9547
- gauge height 10.0 feet
but .30 caliber (meaning 0.30 inch, bore of small arms); 30 calibers (length)
