Time — O'clock, A.M., and P.M.
Numbers
Rulebase Summary
Numbers that precede o'clock are usually spelled out (ten o'clock). Numbers that precede a.m. or p.m. are usually written as figures (9:30 a.m.). Do not capitalize a.m. or p.m. If a.m., p.m., or o'clock is omitted by the speaker, spell out the hour.
Examples
A. We arrived at 10 o'clock that morning.
A. We arrived at ten o'clock that morning.
Numbers preceding o'clock are usually spelled out.
A. The alarm went off at nine-thirty a.m.
A. The alarm went off at 9:30 a.m.
Numbers preceding a.m. or p.m. are usually written as figures.
Transcript Notes
When the court reporter hears 'o'clock,' that is what should be written — the ciphers or zeros that follow a colon in time elements do not stand for the spoken expression 'o'clock.' Some reporters prefer a consistent time format (XX:XX) for ASCII formatting and word searches, but the drawback is that the record will not always be verbatim. When a.m. or p.m. begins a sentence, capitalize the first letter and lowercase the others.
Style Guide References (4)
Morson's
Morson's
BGGP
BGGP