Comments on: 12 P.M. – say what? http://www.squarecirclez.com/blog/standards-lunacy/186 Mathematics, learning, computing, travel - and whatever... Tue, 16 Mar 2010 02:48:59 +0000 http://wordpress.org/?v=abc hourly 1 By: Alan Cooper http://www.squarecirclez.com/blog/standards-lunacy/186/comment-page-1#comment-15484 Alan Cooper Tue, 15 Jan 2008 17:09:28 +0000 http://www.squarecirclez.com/blog/standards-lunacy/186#comment-15484 Actually, I like your idea that 12pm and 12am are both midnight! This acutally *resolves* the ambiguity rather than creating one since 12am is clearly the midnight at the start of the day and 12 pm is the one at the end. And as you point out noon should be called neither pm nor am since it is really just 12m. But then if we wanted to be logical about it perhaps we should also ask why is 1am not called 11am since it comes 11 hours before noon? On the other hand if we think of 12 as meaning 12+epsilon (ie just infinitesimally after 12), which it really is once it shows on the clock, then Michael's convention becomes correct. Of course in any case it should be criminal for airlines or other such agencies not to use a 24hr clock. Actually, I like your idea that 12pm and 12am are both midnight!
This acutally *resolves* the ambiguity rather than creating one since 12am is clearly the midnight at the start of the day and 12 pm is the one at the end. And as you point out noon should be called neither pm nor am since it is really just 12m. But then if we wanted to be logical about it perhaps we should also ask why is 1am not called 11am since it comes 11 hours before noon?

On the other hand if we think of 12 as meaning 12+epsilon (ie just infinitesimally after 12), which it really is once it shows on the clock, then Michael’s convention becomes correct.

Of course in any case it should be criminal for airlines or other such agencies not to use a 24hr clock.

]]> By: Michael http://www.squarecirclez.com/blog/standards-lunacy/186/comment-page-1#comment-15457 Michael Tue, 15 Jan 2008 07:38:07 +0000 http://www.squarecirclez.com/blog/standards-lunacy/186#comment-15457 This is what they taught me at school... 12pm = Midday 12am = Midnight This system is fundamentally flawed. As illustrated by this question: How many hours are between 11am and 12am? (Hint: it's not 1 hour.) This is what they taught me at school…

12pm = Midday
12am = Midnight

This system is fundamentally flawed. As illustrated by this question:

How many hours are between 11am and 12am?
(Hint: it’s not 1 hour.)

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