What do A.M. and P.M. mean?
A.M. and P.M. are abbreviations used with times to show whether they happen in the morning or the afternoon and evening.
- School starts at 8:15 A.M. (in the morning).
- Soccer practice is at 4:30 P.M. (in the afternoon).
A.M. stands for the Latin phrase “Ante Meridiem,” which means “before midday.” P.M. stands for “Post Meridiem,” meaning “after midday.”
How to understand the 12-hour clock
The 12-hour clock divides the day into two halves of 12 hours each. The A.M. half runs from midnight to noon. The P.M. half runs from noon to midnight.
- 12:00 A.M. is midnight, the start of a new day.
- 12:00 P.M. is noon, the middle of the day.
- Times from 12:01 A.M. to 11:59 A.M. are morning times.
- Times from 12:01 P.M. to 11:59 P.M. are afternoon and evening times.
Remember, noon is the turning point. Any time after the clock strikes noon switches from A.M. to P.M.
Connecting times of day with A.M. and P.M.
We use A.M. for activities that happen after midnight and before noon. We use P.M. for activities that happen after noon and before midnight.
- Eating breakfast at 7:30 A.M.
- Reading class at 10:00 A.M.
- Eating lunch at 12:15 P.M.
- Riding the bus home at 2:45 P.M.
- Eating dinner at 6:00 P.M.
- Going to bed at 8:30 P.M.
Think about your daily routine. Most morning activities use A.M., and most afternoon and evening activities use P.M.
Writing and reading times correctly
Always write the abbreviation (A.M. or P.M.) after the time, using periods. When reading a time aloud, say the numbers and then say “A.M.” or “P.M.”
- Write: 9:20 A.M. Read: “Nine twenty A.M.”
- Write: 1:05 P.M. Read: “One oh-five P.M.”
- Write: 11:45 P.M. Read: “Eleven forty-five P.M.”
Two different times can use the same numbers. For example, 10:30 A.M. is in the morning, but 10:30 P.M. is at night. The A.M. or P.M. tells you which one.