# 12am / 12pm - Which is noon? which is midnight?

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#### Dalian

##### Senior Member
I'm confused~help me out [with the use of 12am and 12pm], thank you

Dalian

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• #### lsp

##### Senior Member
We've discussed this numerous times, one of those threads is here. You can find others with the Search function.

#### marget

##### Senior Member
Hi,

Can anyone explain why we say PM for noon when it's exactly, not after, noon? Does it have to do with the day beginning at 12:00 AM which is clearly before noon so we must use PM for lack of anything more precise to express the other 12 o'clock?

#### foxfirebrand

##### Senior Member
We could look at 12N and 12M as ambiguously AM or PM, and be scrupulously mathematical about it forever-- but those of us who have to get on with the business of telling or keeping time have to pick one or the other to assign to each, and that's where convention gets imposed. It's the same case with idiom, which is of course never logical-- it's just the way we say/do it, the way things have sorted out.

I suggest we all switch to military time. Noon is 1200 hrs and midnight is 0000 hrs (pronounced zero hundred). The "wee hours" become "oh-dark-thirty." Synchronize your timepieces on my mark-- three, too, won...click! Problem solved, ball in your court, and smokem if you gottem.
.
.

#### Brioche

##### Senior Member
Hi,

Can anyone explain why we say PM for noon when it's exactly, not after, noon? Does it have to do with the day beginning at 12:00 AM which is clearly before noon so we must use PM for lack of anything more precise to express the other 12 o'clock?

I suggest that it may come from digital clocks, the sort that have two "cards" on show, one with the hour, and one for the minutes.
The hour cards are 1 am, 2 am, 3 am, &c, and the minutes 00, 01, 02, &c.
The cards are on wheels, so that a new card shows each minute.

So the clock shows 11 am :59, then 12 pm: 00, then 12 pm: 01, and so on.

The makers were not going to have special cards with 12 noon and 12 midnight to show for just one minute - it would make the mechanism pretty complicated too.

#### JeffJo

##### Senior Member
Using "12:00 pm" for noon is only a convention, based on simple clocks, I agree. A distinction had to be made, between noon and midnight, for simple clocks, so they used "am" for midnight, and "pm" for noon. Language then followed the clock convention.

"PM" will be correct for times after noon, so it's reasonable enough to use exact 12:00 as the "click-over" point. The click-over to PM at exact noon is made so that it will be correct as the clock continues to run.

Strictly speaking, neither 'am' nor 'pm' applies to exact noon, or to exact midnight, but clocks incapable of displaying "noon" or "midnight" had to show something. In writing and printing, it would still be best to use "noon" or "midnight" when that's what's intended, but people often use the primitive and technically incorrect clock conventions. Writing "12pm" for "noon" isn't really incorrect, it's just, oh, mechanical.

#### panjandrum

##### Lapsed Moderator
A.M. and P.M. start immediately after Midnight and Noon (Midday) respectively.
This means that 00:00 A.M. or 00:00 P.M. (or 12:00 A.M. and 12:00 P.M.) have no meaning.
Every day starts precisely at midnight and A.M. starts immediately after that point in time e.g. 00:00:01 A.M.
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.
Source

Taken from a link provided in:
What time of day is 12AM.

#### Sepia

##### Senior Member
We could look at 12N and 12M as ambiguously AM or PM, and be scrupulously mathematical about it forever-- but those of us who have to get on with the business of telling or keeping time have to pick one or the other to assign to each, and that's where convention gets imposed. It's the same case with idiom, which is of course never logical-- it's just the way we say/do it, the way things have sorted out.

I suggest we all switch to military time. Noon is 1200 hrs and midnight is 0000 hrs (pronounced zero hundred). The "wee hours" become "oh-dark-thirty." Synchronize your timepieces on my mark-- three, too, won...click! Problem solved, ball in your court, and smokem if you gottem.
.
.
Sounds like a good idea - but I must throw in some trivial info here: The way I learned it we'd never start a military operation at 0000h. It would start at 2359h or 0001h. Just with Murphy's Law in our minds - to make sure that nobody, absolutely nobody would have any confusion about the date and launch his attack 24 hours earlier or later.

#### mplsray

##### Senior Member
Using "12:00 pm" for noon is only a convention, based on simple clocks, I agree. A distinction had to be made, between noon and midnight, for simple clocks, so they used "am" for midnight, and "pm" for noon. Language then followed the clock convention.

"PM" will be correct for times after noon, so it's reasonable enough to use exact 12:00 as the "click-over" point. The click-over to PM at exact noon is made so that it will be correct as the clock continues to run.

Strictly speaking, neither 'am' nor 'pm' applies to exact noon, or to exact midnight, but clocks incapable of displaying "noon" or "midnight" had to show something. In writing and printing, it would still be best to use "noon" or "midnight" when that's what's intended, but people often use the primitive and technically incorrect clock conventions. Writing "12pm" for "noon" isn't really incorrect, it's just, oh, mechanical.
I largely agree. I would just take issue with identifying the clock conventions as "technically incorrect." That strikes me as example of the etymological fallacy, just as it would be to say that "It is technically incorrect to say that anyone is melancholy nowadays because melancholy means that a person has an excess of black bile, a theory which has been discredited." The meanings of AM, PM, and melancholy depend upon usage, not upon on their origins.

#### panjandrum

##### Lapsed Moderator
There appears to be a convention that 12am is midnight, 12pm is noon - but that is not universal, else we wouldn't be having this discussion for at least the fourth time in WR Forums.

#### Packard

##### Senior Member
I never use 12:00 (AM or PM) ever! (Except right here and now.) For exactly the reason that this thread has been started. It will (guanranteed) be a cause of confusion at some point or another.

I say: Midnight or Noon. You will never have any ambiguity if you use those words.

You still have to learn the difference because there will always be some less considerate writer who will use "12:00" and you will have to figure out what they meant.

#### JeffJo

##### Senior Member
A.M. and P.M. start immediately after Midnight and Noon (Midday) respectively.
This means that 00:00 A.M. or 00:00 P.M. (or 12:00 A.M. and 12:00 P.M.) have no meaning.
Every day starts precisely at midnight and A.M. starts immediately after that point in time e.g. 00:00:01 A.M.
...
That link, unfortunately, is wrong. "12:00 pm" does, in fact, have a meaning. It means noon. Terms in speech, or writing, have the meanings that people assign to them. The idea of a day starting at midnight is also a human convention. There's no such natural division of days.

An example might help to illustrate why "12 pm" is used to mean noon. Take three clock mechanisms, all highly precise and capable of keeping good time. Attach one mechanism (A) to a display that shows time to the nearest minute. Attach another mechanism (B) to a display that shows time to the nearest second. Attach the third mechanism (C) to a display that shows time to the nearest 1/10 second. Then look at what can happen around noon.

First, set all the mechanisms to switch the display to PM at their first display interval after noon. The following is what you'll get, when the time is 12:00:00 and 1/10 second, PM.

A. shows 12:00 AM - and it is wrong. The time is actually PM.
B. shows 12:00:00 AM - and it is wrong. The time is actually PM.
C. shows 12:00:00.1 PM - and it is right. Only this clock is right with its AM/PM display.

Two of the clocks are wrong on their AM/PM displays, just because of how the display is being operated. If you set all three clocks side-by-side on a table and watch them, you will actually see two of the clocks being wrong about AM/PM. The third clock will show you the other two being wrong, as you watch (even if all three clocks are equally accurate at keeping time.)

Now, change the way the mechanisms activate the displays, so that they all "click" over to PM at 12:00 exactly. Then, you'll see the following at a time of 12:00:00.1 PM.

A. shows 12:00 PM - and it is right. Earlier it was wrong with its AM/PM display, but now it's right.
B. shows 12:00:00 PM - and it's right. This one also was wrong earlier, but is now right.
C. shows 12:00:00.1 PM - and it is right. This one is still right, as it was earlier.

All three clocks now agree with their AM/PM indicators, and they're all correct. You'll never see one of the clocks showing the others to be wrong about AM/PM, just because of how the displays are activated. What it took, to make the clocks agree, is merely the convention that 12 o'clock exactly is "pm."

#### Packard

##### Senior Member
All of which is why the military uses a 24 hour clock.

"Dinner is at 18:00 hours."

#### panjandrum

##### Lapsed Moderator
It really doesn't help to protest that 12pm has a meaning.
It is evident from all the discussion here and elsewhere that neither 12am nor 12pm convey a specific and reliable meaning.
They are both ambiguous.
The longer the discussion goes on, the more apparent this becomes.

#### Packard

##### Senior Member
It really doesn't help to protest that 12pm has a meaning.
It is evident from all the discussion here and elsewhere that neither 12am nor 12pm convey a specific and reliable meaning.
They are both ambiguous.
The longer the discussion goes on, the more apparent this becomes.

My point exactly. Use Noon or Midnight.

#### mplsray

##### Senior Member
There appears to be a convention that 12am is midnight, 12pm is noon - but that is not universal, else we wouldn't be having this discussion for at least the fourth time in WR Forums.
I agree. Nevertheless, when the usage is so lopsided as in is in favor of 12 PM being noon, it's a disservice to suggest to someone asking the meaning of the expression to suggest that there is anything other than a tiny possibility that when they read 12 PM it means midnight.

I'd like to point out that using the term midnight itself is no guarantee of clarity. In fact, midnight on July 13 means both "midnight, the night of July 12-13" and "midnight, the night of July 13-14." Is there a consensus on which meaning is correct? Even if usage is strongly in favor of one over the other, surely there is even a stronger consensus that 12 PM on July 13 means "noon of July 13."

#### Forero

##### Senior Member
Not to mention that noon is closer to 1:00 pm when we have set our watches ahead for the summer.

But here is what has always bothered me about am and pm: If 3 am is 3 hours ante-meridiem, shouldn't that mean 3 hours before noon (what we call 9 o'clock in the morning)?

#### Packard

##### Senior Member
The military has it right: use a 24 hour clock.

#### Packard

##### Senior Member
...I'd like to point out that using the term midnight itself is no guarantee of clarity. In fact, midnight on July 13 means both "midnight, the night of July 12-13" and "midnight, the night of July 13-14." Is there a consensus on which meaning is correct? Even if usage is strongly in favor of one over the other, surely there is even a stronger consensus that 12 PM on July 13 means "noon of July 13."

I was going to write "balderdash!" but instead I will write, "I don't think there is any possibility of confusion when using the word 'midnight'".

For example:

If I were to say, "Meet me at Midnight on Friday." You will know with certainty that 60 seconds after you meet me it will be 12:01 on Saturday morning.

Similarly, if I were to say, "Meet me on July 13th at midnight." You will know with certainty that 60 seconds after you meet me it will be 12:01 on the morning of the 14th.

No confusion at all.

#### panjandrum

##### Lapsed Moderator
In another context completely I have recently noted that 8:31pm occurs long after 12:38pm.
What a strange world we live in.

#### Packard

##### Senior Member
In another context completely I have recently noted that 8:31pm occurs long after 12:38pm.
What a strange world we live in.

???

#### mplsray

##### Senior Member
Originally Posted by panjandrum
"In another context completely I have recently noted that 8:31pm occurs long after 12:38pm.
"What a strange world we live in."

???
To translate: 2031 hours occurs long after 1238 hours.

Of course, panjandrum's point is lost in the translation.

#### panjandrum

##### Lapsed Moderator
To translate: 2031 hours occurs long after 1238 hours.

Of course, panjandrum's point is lost in the translation.
Thank you. Exit panj, bowing, scraping and doffing feather-plumed hat.

#### mplsray

##### Senior Member
I was going to write "balderdash!" but instead I will write, "I don't think there is any possibility of confusion when using the word 'midnight'".

For example:

If I were to say, "Meet me at Midnight on Friday." You will know with certainty that 60 seconds after you meet me it will be 12:01 on Saturday morning.

Similarly, if I were to say, "Meet me on July 13th at midnight." You will know with certainty that 60 seconds after you meet me it will be 12:01 on the morning of the 14th.

No confusion at all.
From the faq of the newsgroup sci.astro:

"In general, the old English A.M./P.M. notation is extremely problematic. A shorter and more obvious time notation is the modern 24h notation in which the hours in the day range from 00:00 to 23:59. This notation even allows one to distinguish midnight at the start of the day [00:00] from midnight at the end of the day [24:00], while the old English notation requires kludges like starting a contract at 12:01 A.M. in order to make clear which of the two midnights associated with a date had been intended."

#### Sepia

##### Senior Member
If you take a closer look at the real meaning of the letters AM or PM you all ought to notice that there is no way that "12am" can make any logical sense. 12pm would mathematically make sense but why use it when "12am" can't be used (logically)?

#### Packard

##### Senior Member
To translate: 2031 hours occurs long after 1238 hours.

Of course, panjandrum's point is lost in the translation.
He is mixing 12 hour clocks with 24 hour clocks. You cannot do that; you end up with gibberish.

There is an old math game you can play with small children. It goes like this:

Adult: How many fingers do you have?

Child: 10

Child: 1, 2, 3, 4, 5; 6, 7, 8, 9, 10.

Child: 10, 9, 8, 7, 6,

Adult: OK. So you have "6" on your right hand, and how many do you have on your left hand.

Child: 5

Adult: OK, 5 + 6 = 11; you have 11 fingers

The point being that you cannot mix addition and subtraction in the same equation like this. You end up with gibberish.

The same is happening when you mix 24 hour clocks and 12 hour clocks. Gibberish.

#### mplsray

##### Senior Member
If you take a closer look at the real meaning of the letters AM or PM you all ought to notice that there is no way that "12am" can make any logical sense. 12pm would mathematically make sense but why use it when "12am" can't be used (logically)?
The trouble with that argument is the phrase "real meaning." It makes sense in this context only if you are arguing that the real (that is, "true") meaning of a word or expression arises from its etymology, and if you do that you become guilty of the etymological fallacy (a logical fallacy which is a subset of the genetic fallacy).

#### Packard

##### Senior Member
Wow. Does anyone know what time it is?

#### panjandrum

##### Lapsed Moderator
In another context completely I have recently noted that 8:31pm occurs long after 12:38pm.
What a strange world we live in.
He is mixing 12 hour clocks with 24 hour clocks. You cannot do that; you end up with gibberish.

[...]

The point being that you cannot mix addition and subtraction in the same equation like this. You end up with gibberish.

The same is happening when you mix 24 hour clocks and 12 hour clocks. Gibberish.
I wasn't mixing anything, I was quoting from another thread. There is an example in this thread - if you happen to be living in the GMT+1 time zone.
I look at the time of Packard's post, 2:32 AM.
Then I look at the time of the post immediately before it, Sepia's post - 12:47 AM.
Yes, in this strange scheme 12:47 comes before 2:32.
I'm not complaining, only supporting the point of view that it is not always possible to apply mathematics to language.

#### roxcyn

##### Senior Member
11:59 PM ----> 12:00 AM. If you use an alarm clock, you must put it as AM. Also my computer says it as AM as well. I am sure it has gone back to tradition. During this time people where asleep and it was considered "night" time, so AM time.

11:59 AM ----> 12:00 PM. Again, it is the similar explanation above. People consider the "morning" time has not gone, and it's time for the rest of the day.

You may want to use the 24 hour system, if you are confused. 12:00 (Twelve hundred hours) or 00:00/24:00 (oh hundred hours / twenty-four hundred hours).

#### mally pense

##### Senior Member
I have to say that as a native English speaker, I get totally confused by references to 12:15am or pm. I've never any idea which one is which.

#### roxcyn

##### Senior Member
I have to say that as a native English speaker, I get totally confused by references to 12:15am or pm. I've never any idea which one is which.
I explained which was which .

12:15 AM = 00/24:15
12:15 PM = 12:15

#### mally pense

##### Senior Member
Yes, I know, but next time the issue arises I will have forgotten yet again. Quarter past midnight I'm happy with, ditto 12:15 meaning just after mid-day, but to me 12:15 AM just doesn't sit comfortably in my brain for just after midnight. No amount of explaining will change that.

#### mplsray

##### Senior Member
Yes, I know, but next time the issue arises I will have forgotten yet again. Quarter past midnight I'm happy with, ditto 12:15 meaning just after mid-day, but to me 12:15 AM just doesn't sit comfortably in my brain for just after midnight. No amount of explaining will change that.
It's worth pointing out that there is no controversy concerning 12:01 AM to 12:59 AM, which is why 12:01 AM is used in contracts instead of 12:00 AM to indicated when a contract provision takes effect at the beginning of a given date.

#### mally pense

##### Senior Member
It's worth pointing out that there is no controversy concerning 12:01 AM to 12:59 AM, which is why 12:01 AM is used in contracts instead of 12:00 AM to indicated when a contract provision takes effect at the beginning of a given date.
I'm sure it is worth pointing this out, but perhaps not all that apposite to quote me in doing so because contractual clarity or ambiguity isn't something that is an issue for my brain when working at this everyday human level of day-to-day thought or conversation. Your point doesn't really follow on from mine in this respect.

No, I think the biggest issue my brain has is in the concept that somehow 12 hours can be considered to have been counted or to have passed at the very start of the day when in fact not even a single hour has passed. (Which is why my brain doesn't have such a problem with 12:15 (am or pm, or no qualifier, no matter) being used to represent a time just after noon. In that instance my brain is aware that roughly 12 hours and some have passed since the start of the day.

I'm saying "my brain", because at this level, I'm not thinking consciously or intellectually, I'm just engaged in basic human interaction, and intellectually I'm pretty much an observer looking on at my brain's "gut reaction" (if that's not too much a contradiction in terms). Contracts, timetables and such can certainly find use in distinguishing times and dates by establishing intellectual conventions and avoiding specific times to circumvent ambiguity, but at the human level, it's nice to be able to refer to these times simply as midnight and noon with absolutely no ambiguity whatsoever (as Packard will no doubt agree) .

By the way, are legal contracts forbidden to use "midnight" and "noon"? I wasn't aware of such a restriction.

But here is what has always bothered me about am and pm: If 3 am is 3 hours ante-meridiem, shouldn't that mean 3 hours before noon (what we call 9 o'clock in the morning)?
Just to pick up on this earlier point: am and pm aren't used as a count forwards or backwards from noon; they're used to indicate one of two halves of the day, i.e. the half that occurs before noon or the half that occurs after noon. 3am is not "three hours before noon", but "three hours after midnight in the 'before noon' half of the day".

#### Sepia

##### Senior Member
Yes, I know, but next time the issue arises I will have forgotten yet again. Quarter past midnight I'm happy with, ditto 12:15 meaning just after mid-day, but to me 12:15 AM just doesn't sit comfortably in my brain for just after midnight. No amount of explaining will change that.

That is just about what I was pointing out further up.

AM meaning Ante Meridiem = before mid-day could makes no logical sense with a time referring to mid-day.

Noon is neither AM nor PM, when AM and PM mean before and after Noon.
12 hours before or after Noon would both be Midnight.

However, 15 Min after Midnight is definitely AM because within its 24 hour period it is before Noon.

#### mally pense

##### Senior Member
...when AM and PM mean before and after Noon...
Well they do and they don't mean this. Yes they do in the sense the that first half of the day is before noon and the second half of the day is after noon, but they're certainly not used in the sense of noon providing a reference point for counting hours before or after. No more so in fact than "afternoon" is used as a counting reference, which is why we say "I'll see you this afternoon" or "I'll be there in the afternoon" and not "I'll be there three hours afternoon" (sic).

AM and PM are used in this way too, i.e. to refer to periods of time (with 12 hours in each) rather than as some sort of continuous temporal metric. Hence, regardless of my concerns for the basic human level of comprehension (or otherwise) of 12 am/pm, "12am" does NOT mean twelve hours before noon, it means twelve o'clock in the before-noon half of the day (even if it arguably happens to give the same result in this specific instance).

#### Sepia

##### Senior Member
Well they do and they don't mean this. Yes they do in the sense the that first half of the day is before noon and the second half of the day is after noon, but they're certainly not used in the sense of noon providing a reference point for counting hours before or after. No more so in fact than "afternoon" is used as a counting reference, which is why we say "I'll see you this afternoon" or "I'll be there in the afternoon". AM and PM are used in this way too, i.e. to refer to periods of time (with 12 hours in each) rather than as some sort of temporal metric. Hence, regardless of my concerns for the basic human level of comprehension or otherwise of 12 am/pm, "12am" does NOT mean twelve hours before noon, it means twelve o'clock in the before-noon half of the day (even if it happens to give the same result in this specific instance).

Yes, sure, but this logic still supports your argument and other people's argument for using Noon and Midnight, doesn't it?

#### expenseroso

##### Senior Member
Hmm... I've seen 12:00 AM and 12:00 PM used quite a bit. Although, if it isn't immediately clear from the context, it still takes a second for me to process, I'd never think of either as being incorrect. Noon and midnight are certainly preferable if you want to increase the fluency with which your writing/speech is understood (and why wouldn't you?).

#### mally pense

##### Senior Member
Yes, sure, but this logic still supports your argument and other people's argument for using Noon and Midnight, doesn't it?
Yes, though I'm really not arguing a case proactively. Like expenseroso, I'm just saying that it doesn't sit comfortably with my brain, or as he puts it more specifically, it still takes a second or so to process and neither of them will ever be thought of as correct. But as long as the people I know continue to use language such as "I got in just after midnight" in real life I'll be happy.

#### JulianStuart

##### Senior Member
But here is what has always bothered me about am and pm: If 3 am is 3 hours ante-meridiem, shouldn't that mean 3 hours before noon (what we call 9 o'clock in the morning)?
I was confused by that until I realized that the am or pm part of a time just tells you which 12hour interval is being used for the clock face. It doesn't mean 3 hours before meridian (like I thought) it means 3 o'clock when the clock is showing the 12 hours before midday (I'm sorry, before noon ) Or "It's 3 hours since the clock face went from displaying pm to displaying am"

Now, for the pm 12 hrs clock face, the numbers do actually match the number of hours post midday noon

Let's not think about 3 am meaning 3 hours After Midnight

#### Rover_KE

##### Senior Member
Hi,

Can anyone explain why we say PM for noon when it's exactly, not after, noon?
The precise instant of noon only lasts for a nanosecond (or probably less than that).

We have no time to register this moment before it's already after noon (PM).

Rover

#### Peter Tran

##### Senior Member
As we know that the time between midnight and noon, we have to say a.m after the time such as 3 a.m, 7 a.m etc... and from noon till midnight it should be p.m following the time such as 1 p.m, 10 p.m. But why at 12 o'clock at noon, it becomes 12 p.m and 12 o'clock at midnight -it's called 12 a.m. Please particularly explain that to me. It makes me get confused.

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#### Egmont

##### Senior Member
We say 12:00 a.m. for midnight to be consistent with 12:01 a.m., 12:02 a.m., and so on through 12:59 a.m. It's the same for p.m.

People who want to be certain of avoiding confusion will say "12 noon," often abbreviated 12n, or "12 midnight," which can be abbreviated as 12m - or they use a 24-hour clock.

#### Hau Ruck

##### Senior Member
There is neither a 12 a.m. nor a 12 p.m.
There is only 12 noon and 12 midnight.

12:01 a.m./p.m. is possible, as is any of the other 58 minute markers.

a.m. actually stands for Ante Meridiem (before noon) and p.m. stands for Post Meridiem (after noon).

12:00 a.m./p.m. is never a real thing.

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#### Copperknickers

##### Senior Member
Sorry Filsmith but you are incorrect. 12.00 a.m. is always understood to be midnight, and 12.00 p.m. is always understood to be midday. Look on any clock which differentiates between them.

The reason is obvious: 12.00 a.m. is officially the start of the new day, so there hasn't been a noon yet, hence it is before noon. 12.00 p.m. therefore is after noon (technically it should be 12.00 m. and then 12.01 p.m etc. but that is overcomplicating things).

#### Hau Ruck

##### Senior Member
Sorry Filsmith but you are incorrect. 12.00 a.m. is always understood to be midnight, and 12.00 p.m. is always understood to be midday. Look on any clock which differentiates between them.

The reason is obvious: 12.00 a.m. is officially the start of the new day, so there hasn't been a noon yet, hence it is before noon. 12.00 p.m. therefore is after noon (technically it should be 12.00 m. and then 12.01 p.m etc. but that is overcomplicating things).
No, I'm sorry, but that is not correct. By the very definition of Ante Meridiem and Post Meridiem, there is no such thing as 12:00 a.m. or 12:00 p.m. There is a 12:01 a.m./p.m., 12:02 a.m./p.m., 12:03 a.m./p.m., 12:04 a.m./p.m., etc. It is impossible to have an actual 12:00 a.m. or 12:00 p.m.

I can assure you that this topic is quite heavily covered out there in the world of google.

#### Copperknickers

##### Senior Member
No, I'm sorry, but that is not correct. By the very definition of Ante Meridiem and Post Meridiem, there is no such thing as 12:00 a.m. or 12:00 p.m. There is a 12:01 a.m./p.m., 12:02 a.m./p.m., 12:03 a.m./p.m., 12:04 a.m./p.m., etc. It is impossible to have an actual 12:00 a.m. or 12:00 p.m.

I can assure you that this topic is quite heavily covered out there in the world of google.
I don't know the technicalities of it, but this forum is for language, not metaphysics. No amount of googling can take away from the fact that 90% of English speakers know that 12.00 a.m. is midnight and 12.00 p.m. is midday. Nor can it take away from the fact that 12.00 a.m. comes before 12 noon on any given day.

#### Andygc

##### Senior Member
the fact that 90% of English speakers know that 12.00 a.m. is midnight and 12.00 p.m. is midday.
Do you have any evidence to support that fact? I am happy to be in the alleged 10% that has never thought that midnight and midday could be described as 12 am and 12 pm. I am fascinated by the metaphysical and existential conundrum posed by 12 pm trying to be both itself and after itself at the same time. This ranks with questions such as "Is Time a Mobius Strip?" and "The answer is 42, but what is the question?"

#### Packard

##### Senior Member
...No amount of googling can take away from the fact that 90% of English speakers know that 12.00 a.m. is midnight and 12.00 p.m. is midday. Nor can it take away from the fact that 12.00 a.m. comes before 12 noon on any given day.
Count me amongst the 10% who live in the dark. I can never get it clear in my mind if a.m. means noon or midnight.

(I also confuse "top up/top down" in convertible automobiles--so this may be more to do with the way my mind works that language.)

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