Is midnight 12 AM or PM?
Is noon 12 AM or PM?
What does pm am mean?
I was talking to a native speaker (American woman ) and she corrected me as I was talking to her that 12 PM is the one in the day time not 12 AM. I don’t know if I have had it wrong all my life or what.
If 12 AM is midnight, why is 12 PM noon? Shouldn’t “AM” stand for after midnight and “PM” after morning?
time - Is it correct to say "12:00am"? - English Language & Usage Stack Exchange
CMV: It would make more sense for 12 PM to be midnight and 12 AM to be noon
12 am and 12 pm are wrong and should be switched.
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It feels backwards—12 noon is exactly halfway between midnights, but we call it PM. Wouldn’t it make more sense for 12 noon to be AM, since it’s before the second midnight?
The Wikipedia article 12 Hour Clock is worth quoting at length:
Confusion at noon and midnight
It is not always clear what times "12:00 a.m." and "12:00 p.m." denote. From the Latin words meridies (midday), ante (before) and post (after), the term ante meridiem (a.m.) means before midday and post meridiem (p.m.) means after midday. Since strictly speaking "noon" (midday) is neither before or after itself, the terms a.m. and p.m. do not apply. However, since 12:01 p.m. is after noon, it is common to extend this usage for 12:00 p.m. to denote noon. That leaves 12:00 a.m. to be used for midnight at the beginning of the day, continuing to 12.01 a.m. that same day.
However, because practical confusion is still possible, some style guides recommend replacing "12:00 p.m." with "12:00 noon" and "12:00 a.m." with "12:00 midnight".
The American Heritage Dictionary of the English Language (Fourth Edition, 2000) has a usage note on this topic: "Strictly speaking, 12 a.m. denotes midnight, and 12 p.m. denotes noon, but there is sufficient confusion over these uses to make it advisable to use 12 noon and 12 midnight where clarity is required."
Many U.S. style guides, and NIST's "Frequently asked questions (FAQ)" web page, recommend that it is clearest if one refers to "noon" or "12:00 noon" and "midnight" or "12:00 midnight" (rather than to "12:00 p.m." and "12:00 a.m."). Some other style guides suggest "12:00 n" for noon and "12:00 m" for midnight.
The Canadian Press Stylebook (11th Edition, 1999, page 288) says, "write noon or midnight, not 12 noon or 12 midnight." Phrases such as "12 a.m." and "12 p.m." are not mentioned at all.
The use of "12:00 midnight" or "midnight" is still problematic because it does not distinguish between the midnight at the start of a particular day and the midnight at its end. To avoid confusion and error, some U.S. style guides recommend either clarifying "midnight" with other context clues, or not referring to midnight at all. For an example of the latter method, "midnight" is replaced with "11:59 p.m." for the end of a day or "12:01 a.m." for the start of the next day. That has become common in the United States in legal contracts and for airplane, bus, or train schedules, though some schedules use other conventions.
My advice is to use "12:00 noon" instead of "12:00 p.m." and "12:00 midnight" instead of "12:00 a.m." Realize that readers may be confused which day 12:00 midnight belongs to, so make sure context makes it clear.
12:00am is correct.
The clock goes from 12:00am (midnight) through 1:00am, 2:00am to 11:59am and then to 12:00pm (noon) through 1:00pm to 11:59pm and repeats.
It seems no more strange to go from 12:59 to 1:00 than it does to go from 11:59pm to 12:00am