AM and PM are also written A.M. and P.M., a.m. and p.m., and am and pm. Some put a space between the time and AM or PM.
• 8 AM
• 3:09 P.M.
• 11:20 p.m.
Others write times using no space before AM or PM.
For the top of the hour, some write 9:00 PM, whereas others drop the :00 and write 9 PM (or 9 p.m., 9pm, etc.).
Using numerals for the time of day has become widely accepted.
• The flight leaves at 6:22 a.m.
• Please arrive by 12:30 sharp.
However, some writers prefer to spell out the time, particularly when using o’clock.
• She takes the four thirty-five train.
• The baby wakes up at five o’clock in the morning.
NOTE: Just in case you don’t know what’s the meaning of AM and PM, here’s an easy way to remember which is which; AM means After Midnight and PM means Past Morning. AM (Ante Meridiem) and PM (Post Meridiem) are Latin abbreviations.
How do you tell the time when it strikes at 12 in the afternoon (12 PM) or 12 at night (12 AM)? Most ESL speakers will say “It’s 12 PM” for 12 in the afternoon and “It’s 12 AM” for 12 at night/midnight.
INCORRECT: I have an appointment at 12 PM today.
CORRECT : I have an appointment at 12 noon today.
Midday – This is the middle of the day, also called noon (12:00 hours). We don’t say
“12 PM”, but we say “12 noon” or “12 midday”.
Midnight – This is the middle of the night (00:00 hours). We don’t say
“12 AM”, but we say “12 midnight”.