“My contract starts at 12 p.m. on Monday.”
Usage Entry 1391 / 1605 60-second read
Midnight vs. 12 a.m.
Either nominally 12:00 a.m. or 12:00 p.m., depending on convention.
The comparisoni
“My contract starts at 12 a.m. on Monday — but in practice, write "midnight Sunday/Monday" to avoid confusion. The 12 a.m./p.m. convention is famously ambiguous.”
The ruleii
¶
Use MIDNIGHT or NOON to be unambiguous.
NOON is unambiguously 12 p.m. (post meridiem) and MIDNIGHT is unambiguously 12 a.m. (ante meridiem) by convention — but many people get this backwards because midnight is technically neither AM nor PM (it's the boundary). Style guides recommend writing "midnight" or "noon" rather than 12 a.m./p.m.
Memory aidiii
Remember it like this
Just write midnight.