Right on Time
Do you know the right way to write any time of day?
Telling time is easy, but do you get confused over matters like whether to write p.m., P.M. or PM, or if you should add a space, as in 11:35p.m. or 11:35 p.m.?
So little time and so many options!
The following guidelines address common misconceptions about writing time correctly:
1. Style guides differ in terms of capitalizing the names of time zones. If you are not required to follow a particular format, then choose one and stick with it.
- Some capitalize each word, as in Eastern Standard Time, Central Daylight Time, and Mountain Standard Time.
- Other sources capitalize only the proper names. For instance, they capitalize the word Pacific in Pacific daylight time, but not eastern in eastern standard time.
2. Use the singular form of the word saving (not savings) when referring to daylight saving time (DST).
3. Always capitalize the abbreviations for time zones without periods.
- EST, CDT, MST, etc.
4. Put one space without commas between the time and the zone.
- 1:00 a.m. EST
5. The most commonly preferred abbreviations used to indicate before noon (ante meridiem) and after noon (post meridiem) are a.m. and p.m.
- Also accepted are A.M., AM, P.M. and PM., sometimes shown in a slightly smaller font. Whether or not you use periods depends on the style guide or the format you adopt. Maintain the same format throughout any single communication or group of publications.
- Some informal users also opt for am and pm with no periods.
- Pay attention to your spacing—one space between the time and a.m. or p.m., and no spaces between a and m or p and m—with or without periods.
Correct
- 1:30 a.m.
- 1:45 AM
Incorrect
- 2:15p.m.
- 2:30 P M
6. Most style guides state not to show minutes when expressing a.m. and p.m. on the hour.
Correct
- 1 a.m.
- 10 PM
Avoided
- 1:00 a.m.
- 10:00 PM
7. However, facilitate a cleaner, easier-to-read format by including the minutes on the hour when presenting an agenda with multiple times.
- Agenda for Conference
8:00 a.m. Registration
8:30 a.m. Introductions
9:00 a.m. First Speaker
9:30 a.m. Second Speaker
8. Do not use a.m. or p.m. with 12:00.
- The middle of the day is 12:00 noon.
- The middle of the night is 12:00 midnight.
9. When using the 24-hour clock, omit a.m. and p.m., but indicate a time zone if your audience needs clarification.
- 00:00 CST
- 14:30 EST
10. Do not mix a.m. or p.m. (or their other abbreviated forms) with words.
- Correct
· The meeting is at 5 p.m.
· The meeting is at 5 o’clock in the afternoon.
· The meeting is at five o’clock in the afternoon.
- Incorrect
· The meeting is at five p.m.
· The meeting is at 5 o’clock p.m.
11. As shown above, if ending a sentence with p.m. or a.m., do not add an extra period.
12. Write o’clock only when indicating the full hour or when specifying minutes before stating the hour.
- Correct
· 2 o’clock
· two o’clock
· ten past two o’clock
- Incorrect
· 2:10 o’clock
13. Do not separate the words representing the hour and minutes with a hyphen or colon.
Correct
- The wedding would take place at six thirty in the evening.
- The meeting time is six fifteen.
Incorrect
- The wedding would take place at six-thirty in the evening.
- The meeting is at six:fifteen.
14. Use hyphens when writing minutes only if you would normally spell the cardinal number with a hyphen.
- The wedding did not begin until six forty-five.
- My watch read six twenty-two when the meeting started.
15. If the hour and minutes are written in word form and the time serves as an adjective, then hyphenate the hour-minute pair. Do not hyphenate numerals.
- I have a five-fifteen appointment.
- I have a 5:15 appointment.
- I have a five o’clock appointment.
- The schedule shows a six-ten arrival.
- The schedule shows a 6:10 p.m. arrival.
At this point in time, can you confidently determine which are correct?
1. 1 p.m.
2. 1 PM
3. 12:00 noon
4. 12 o’clock noon
5. twelve o’clock in the afternoon
6. all of the above
Good for you if all of the above was your choice! If not, simply keep this reference in a handy place. By taking a little time to verify and adopt applicable rules and styles, you’ll form a habit of writing time correctly without giving the matter a second thought!
My best to you,
Sallie W. Boyles, a.k.a. Write Lady