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Author Topic: Is it 12pm or AM?  (Read 4699 times)

Offline thedoc

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Is it 12pm or AM?
« on: 17/04/2015 19:50:02 »
Neil Price  asked the Naked Scientists:
   Time, why all the confusion about 12AM & 12PM.

Noon is actually 12 o'clock AM (followed by 12:01AM, 12:02AM, ... 12:59AM, 1:00PM)Midnight is actually 12 o'clock PM (followed by 12:01PM, 12:02PM, ... 12:59PM, 1:00AM)I run the Weather Detective citizen scientist program and they insist that 12pm is 12am! How can this be?Their clock reads 12am, 1am, 2am through to Noon (in my book thats 12am) and goes on to read 10pm, 11pm 12AM? They insist that their scientists are correct. As a reference have a look at http://www.simplecodeworks.com/IQ/midnight.html   I'm confused, all the clocks in my position read as normal, are the so called scientists really suggesting that we redefine the time system?

Regards,
Neil W Price


   

What do you think?
« Last Edit: 17/04/2015 19:50:02 by _system »


 

Offline chiralSPO

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Re: Is it 12pm or AM?
« Reply #1 on: 17/04/2015 20:34:02 »
from midnight until noon is AM (AM = ante meridiem = before midday) and from noon until midnight is PM (PM = post meridiem = after midday)

I believe the link you provide incorrectly asserts that meridiem refers to the middle of the sky rather than the middle of the day.

The main purpose of AM and PM, though is to have a standard that everybody uses, so even if the meaning today is different from what may have been or could be reinterpreted, why would we want to change it from what everybody uses?

If you want to be sure to avoid confusion, just refer to the 24-hour clock.
« Last Edit: 17/04/2015 21:15:53 by chiralSPO »
 

Offline alancalverd

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Re: Is it 12pm or AM?
« Reply #2 on: 18/04/2015 09:10:33 »
The time at the north pole, south pole, all military installations, ships, aircraft, GPS satellites, deep space probes, and everywhere else in the universe, is UTC (roughly what used to be called "Greenwich time") . When I am king of the world, there will be no time zones, "daylight saving" (what a lie!) or date line on this planet either: like every intelligent being in the universe, all humans will use UTC.
 

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Re: Is it 12pm or AM?
« Reply #3 on: 18/04/2015 10:43:15 »
That is a brilliant idea, Mr. Alan! I actually just switched my clock to UTC and Am planning to calibrate myself to it.
By the way... Are you the one who said that turning vegetarian would help reduce global warming more than if we reduce carbon emissions?
« Last Edit: 18/04/2015 10:46:07 by Jasper Hayden »
 

Offline evan_au

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Re: Is it 12pm or AM?
« Reply #4 on: 18/04/2015 12:50:52 »
Quote from: chiralSPO
from midnight until noon is AM (AM = ante meridiem = before midday) and from noon until midnight is PM (PM = post meridiem = after midday)
So noon itself is neither before midday, nor after midday - it is midday!
So I suggest that there is no "right" answer for identification of noon as 12AM or 12PM; it is purely a convention - a convention with less than universal acceptance.

Quote from: alancalverd
When I am king of the world, ...all humans will use UTC
I'm sorry to be the one to break it to you, but as a resident of the antipodes, I can assure you that Australians will not vote for you as king of the world.

A 10-hour time change would be most confusing for children at school - when they read in a book that something happened at 3pm (or 15:00), they would imagine events occurring in the black of night. In fact, some of our northern residents voted against even a 1 hour timezone shift for daylight savings.
 

Offline alancalverd

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Re: Is it 12pm or AM?
« Reply #5 on: 18/04/2015 18:07:46 »
Quote
A 10-hour time change would be most confusing for children at school - when they read in a book that something happened at 3pm (or 15:00), they would imagine events occurring in the black of night. In fact, some of our northern residents voted against even a 1 hour timezone shift for daylight savings.

Exactly my point! Having tried to catch a cable TV program in Queensland, you have to know not only what the local time is, but what time it is at the place of transmission, and whether they are running on summer time.

What possible confusion? If I read about an event occuring in Norway or the southern tip of New Zealand at 10 pm it might be bright daylight or pitch dark depending on the season. But if I read about it occurring at 2200 UTC, at least I know what time it was when the perpetrator phoned his boss in Moscow - it was 2200 UTC. Don't you Aussies teach kids anything about geography?
 

Offline David Cooper

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Re: Is it 12pm or AM?
« Reply #6 on: 18/04/2015 18:21:42 »
I have just adjusted the hour on a Casio watch to make sure it does what I thought it would, and it does. On reaching 12 the "p" either appears or disappears, so 12 always acts as if it is 0.
 

Offline syhprum

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Re: Is it 12pm or AM?
« Reply #7 on: 21/04/2015 13:30:43 »
I think you would have a problem converting the Americans all their space probes run on eastern time
 

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Re: Is it 12pm or AM?
« Reply #7 on: 21/04/2015 13:30:43 »

 

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