My parents gave me a curfew of 12 am for a party. I know they wanted me to come home by midnight, so I did. But technically could this really be noon?

And what do am and pm stand for?

First, a.m. is short for 'ante meridiem' - Latin for 'before midday'. P.m. is short for 'post meridiem' - 'after midday'.

Midnight is a thorny question which has come up in Q & A forums many times. It is equidistant from the midday before and the one after, so it is both a.m. and p.m. This is why the military don't use it, but use 23.59 (one minute before midnight) or 00.01 instead as appropriate.

Your curfew in Alison Wonderland was definitely not midday, but it would have been clearer and simpler if your parents had said 'midnight'.

Click here to find the following at the Greenwich Mean Time site, which must be considered among the authoritative sources on this matter"

"AM and PM start immediately after Midnight and Noon (Midday) respectively.

This means that 00:00 AM or 00:00 PM (or 12:00 AM and 12:00 PM) have no meaning.

Every day starts precisely at midnight and AM starts immediately after that point in time e.g. 00:00:01 AM (see also leap seconds)

To avoid confusion timetables, when scheduling around midnight, prefer to use either 23:59 or 00:01 to avoid confusion as to which day is being referred to.

It is after Noon that PM starts e.g. 00:00:01 PM (12:00:01)"

Please note that the blue above, for emphasis, is mine.

May I also advise that you respect what you know your parents mean, even if they select the wrong way to express it? Life can be much happier that way, for them and for you...'fuse.

I understand the Latin derivation, and I respect Greenwich Mean Time (even if their time is shabby or unkind). But etymologies are word histories not rules. The Greeks thought there was some Golden Age when language was perfect, one which needed to be returned to, hence "etymology"&mdash"true word." Words mean what they come to mean for native speakers.

"A.M." for the average person means "morning or late at night"; "P.M." means "in the afternoon, evening, or early night." "12:00 p.m." means the twelve o'clock in the afternoon, not twelve o'clock after noon—and not the twelve o'clock that's late at night (12 a.m.).

This is not like "irregardless," which makes no sense. This is normal usage that don't fit a purist definition.

quote:

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Originally posted by referenth:

"12:00 p.m." means the twelve o'clock in the afternoon, _not_ twelve o'clock after noon.

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Eh? I do hear what you're saying, Ref, and we all break the rules sometimes - but it helps to know the rules so that we know how far off we have gone.

"12am" is midnight. "12pm" is noon. "AM" begins at 12:00 (midnight, 00:00 hrs) and goes through 11:59. "PM" then begins at 12:00 (noon) and goes through 11:59 at night (or, 23:59 hrs).

"Am" and "pm" stand for "ante meridiem" and "post meridiem" (Latin for "before noon" and "after noon"). In the old tradition derived from Latin, noon itself is neither before nor after noon, and noon is denoted "12 m", where "m" stands for "meridies" (Latin for "noon").
Thus: "12 m" is "noon," while "12 pm" is "midnight."
http://www.geocrawler.com/archives/3/379/1997/10/0/2076165/