# Is NOON written as 12AM or 12PM? **URL:** \ **Category:** Factual Questions\ **Created:** [October 4, 2000, 2:21am UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566 "2000-10-04T02:21:38Z")\ **Posts on this page:** 8\ **Page:** 3
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [October 5, 2000, 10:05pm UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/41 "2000-10-05T22:05:00Z")
> [@](#): > > \*Originally posted by nonoMAN \* > **All I’m hearing is a bunch of speculation. . . .** That must be those voices in your head, nono. Read the OP again: **Is NOON written as 12AM or 12PM?** The _ **ANSWER** _ to that question is that, of the two alternatives offered, noon is written 12PM. Sure, it’s also written other ways (“noon,” “1200”) but that doesn’t address the spirit of the question. There may be people wandering around out there who, in taking a brave stand of individualism against the oppressive clarity of standard English, defiantly write “12AM” when referring to noon; these people are _wrong_. For that matter, there are also people who manage to get through life with their head lodged firmly in their lower intestine, but we all agree that doesn’t make it a lifestyle choice that has much to recommend it. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [October 5, 2000, 10:51pm UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/42 "2000-10-05T22:51:20Z")
**lawoot** : 0000 is midnight in official Military Time. Why? 0000 is the first moment of the new day. All time is measured as time elapsed since midnight, therefore midnight is all zeros. I don’t know why anyone would ever use 2400. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [October 5, 2000, 11:27pm UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/43 "2000-10-05T23:27:16Z")
> [@](#): > > \*Originally posted by nonoMAN \* > \*\*All I’m hearing is a bunch of speculation. People have made marginally convincing arguments in both directions. So, I ask you, what source would convince you to change your position? I ask in the hopes of seeing a quoted source other than some alarm clock made in Taiwan for 4cents on the dollar. \*\* _Hey!_ Danged alarm clock snobs. Peace, mangeorge ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [October 5, 2000, 11:35pm UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/44 "2000-10-05T23:35:25Z")
> [@](#): > > \*Originally posted by nonoMAN \* > \*\*All I’m hearing is a bunch of speculation. People have made marginally convincing arguments in both directions. So, I ask you, what source would convince you to change your position? I ask in the hopes of seeing a quoted source other than some alarm clock made in Taiwan for 4cents on the dollar. \*\* _Hey_ Danged alarm clock snobs. Peace, mangeorge ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [October 6, 2000, 12:58am UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/45 "2000-10-06T00:58:06Z")
Here is the response I received from the U.S. Naval Observatory (bolding mine): > [@](#): > > Designation of Midnight and Noon > > There is no official designation that 12:00 Midnight and 12:00 Noon are either AM or PM. Therefore, the U.S. Naval Observatory has adopted the following designations. > > **12:00 Midnight is AM** > > \*\*12:00 Noon is PM \*\* > > However, for official purposes, it is recommended that the 24 hour system be used, where 00:00:01 is the beginning of the day and 24:00:00 is the end of the day. This is the military definition of the 24 hour system. > > Mihran Miranian > Deputy Director > Time Service Department > > U.S. Naval Observatory ---
**Author:** ![lawoot](https://avatars.discourse-cdn.com/v4/letter/l/35a633/32.png) [@lawoot](https://boards.straightdope.com/u/lawoot)\ **Post date:** [October 6, 2000, 1:50am UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/46 "2000-10-06T01:50:27Z")
> [@](#): > > \*Originally posted by Derleth \* > \*\ ***lawoot** : > 0000 is midnight in official Military Time. Why? 0000 is the first moment of the new day. All time is measured as time elapsed since midnight, therefore midnight is all zeros. I don’t know why anyone would ever use 2400. \*\* > [@](#): > > However, for official purposes, it is recommended that the 24 hour system be used, where 00:00:01 is the beginning of the day and 24:00:00 is the end of the day. This is the military definition of the 24 hour system. > > ``` > Mihran Miranian > Deputy Director > Time Service Department > > U.S. Naval Observatory > > ``` Well, I guess that’s why ---
**Author:** ![Kupek](https://avatars.discourse-cdn.com/v4/letter/k/90db22/32.png) [@Kupek](https://boards.straightdope.com/u/Kupek)\ **Post date:** [October 6, 2000, 1:56am UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/47 "2000-10-06T01:56:13Z")
That actually doesn’t solve anything, since they stated themselves there is no official designation, they just adopted a convention. (I personally stand by noon and midnight not being either, as stated in Cecil’s [article](http://www.straightdope.com/classics/a1_130.html) on it.) ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [October 6, 2000, 3:05am UTC](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566/48 "2000-10-06T03:05:51Z")
Given that an “instant” is no time; or rather, an "instant is that _point_ (and remember a point has no dimension) at .0(repeating to infinity), _exactly_ noon or midnight have no practical meaning. Since, when asked the time, we usually say “12:00” or “12:01”, for practical purposes 12:00 lasts for a time in instant past 12:00:00(repeating to infinity, plus repeating to infinity plus .0 repeating to infinity, plus… plus 1) until some time that we decide to call the time “12:01”, noon is for practical purposes PM. **nonoMan** asked for an authorative quote. I’ve provided one. While the USNO correctly points out that the _instants_ of noon an midnight are neither AM nor PM, they say that as a practical matter 12:00 noon is PM and 12:00 midnight is AM. > [@](#): > > they stated themselves there is no official designation … and they go on to say unequivocally that noon is PM and midnight is AM. How much more clear do you want it. That’s their official response. Any nitpicking has no practical value since an instant can’t be recognized. Even if you _could_ recognize the exact instant of noon, the impulses in your sensory system take time to pass the information to your brain… and the instant has passed. If you could stop time at the instant of noon, then you would not be able to perceive it because time has stopped. We all concede that precisely noon and precisely midnight are neither AM nor PM; but as officially recognized, cited, used, and for all practical purposes… \*\*12:00 Midnight is AM 12:00 Noon is PM \*\* [Previous page](https://boards.straightdope.com/t/is-noon-written-as-12am-or-12pm/35566.md?page=2)