Time

[dachse]

Seem to see 12am or 12pm quoted alot these days. I was always tought that there was no such thing, it is either 12 midnight or 12 midday.

So is 12am midnight or midday?

[Bob04]

Midnight

[dachse]

Does everyone agree with that??

[NiceCupOfTea]

yup.

[Gnisy]

The scene: Night time
12 hour timezone: 11.30 pm >> 11.59 pm >> 12.00 am
24 hour timezone: 2330 >> 2359 >> 0000

Lunchtime would be 1200 hours or 12pm.
So ya, 12 am is midnight or 0000 hours.

[Nyza]

in total agreeance with that as it has always been my understanding.

cheers

[SteveD]

12.01am is a minute after midnight and 12.01pm is a minute after midday so logically 12am is midnight and 12pm is midday.

Furthermore, "am" = ante meridiem (before noon) and "pm" = post meridiem (after noon).

[Quizmonster]

Some people apparently use 12 AM to mean midnight and 12 PM to mean midday. However, there really is no 12 AM or 12 PM. Why? Because, as already explained, the letters AM stand for 'ante meridiem' = before the middle of the day and PM stands for 'post meridiem' = after the middle of the day. Since 12 noon actually is the middle of the day, how could it possibly be either 'before' or 'after' itself? The same applies to 12 midnight, which is equidistant from noon, whichever way around you look at it, so it's no more before noon than it is after noon!
This is why a new day starts at 000001 AM...ie one second after midnight. The military and all major time-tablers have no time for midnight such as 2400 or 0000...they invariably use 2359 or 0001.
Click on the following links and you will be taken to web-pages which confirm the non-existence of 12 AM/PM.
http://www.greenwichmeantime.com/info/noon.htm

http://www.physics.nist.gov/News/Releases/questions.html

[dachse]

Thanks to Quizmonster for the link, this reinforces my original thoughts that 12am or 12pm is incorrect.

[jno]

QM is quite right; logically there can be no 12am or 12pm. But people sometimes speak illogically, and when they do so I think it's generally understood that 12am is midnight. I guess this is because 'am' seems to people to mean 'early and late morning' and 'pm' means 'afternoon'; on that basis 12am seems to suggest the middle of the night more than the middle of the day.

[croft-inn]

12 midnight does not exist because it is 00.oo hours. the two seconds between 11.59.59 and 12.00.01 do not exist in time. 12am is lunchtime as the 24 hour clock begins at zero at midnight. Our current use of a 12 hour clock has caused the problem.

[Quizmonster]

The problem with "speaking illogically", Jno - which obviously many people do - is that in this case they also do not agree which way around their illogicality is going to go! Thus, there is no total agreement as to which one of the 12s they are going to adorn with the 'a' for 'ante' or which the 'p' for 'post'. We can see this right here within the ten responses so far offered. That's why one must try to get them to speak "logically".

[jno]

Quite a task you have set yourself there, QM - make sure you have plenty of hot coffee and a change of socks!

[geo0939]

Just as an aside; when I was called up for National Service I was told that I wasn't a soldier 24 hours a day as people thought. In fact I had a full 2 minutes to myself which was 23.59 to 00.01 since there was no such time as Midnight in the army.

[Quizmonster]

I'll try to proselytise, Jno, only when this perennial question crops up here on AnswerBank. I have no intention of setting off on a worldwide crusade! Thus, I can keep just a light knapsack to hand.