Why is 11 am and 1 hour == 12:00 pm?

Post by FabHK » Mon, Jan 08, 2018, 11:30 PM UTC

Symbiote wrote: post #12

ktpsns wrote: post #2

I don't want to be offensive, but this is just another example where anglo-american standards for time and length measurements are ill-defined and lead to confusion. Instead, we have the SI system for the rest of the world and we have international standards for counting time -- with time going from 00:00:00 to 24:59:59 a day. I wonder why people refrain to adopt a working system in favour of culture. I never underst…

> anglo-american Do Spanish-American (and others) use kilos, metres, Celsius and all the rest? I'd assumed not, since the Quebecers I know use American measurements for their body and cooking. But I'd like to be wrong. (You could also have meant anglophone, but that's too broad. 23:05 is fully understood in Britain, and the normal way to write the time on timetables and so on.)

Post by naikrovek » Mon, Jan 08, 2018, 11:33 PM UTC

FabHK wrote: post #27

naikrovek wrote: post #11

Earlier quoted context omitted.

I believe the actual answer is that there is no 12:00 AM or PM. You're meant to say "twelve noon" or "twelve midnight" rather than AM or PM for this exact reason. "actual answer" is maybe a bit strong - I read it somewhere but I can't remember where. The site or book or wherever it was that I read that did seem quite authoritative on the matter, however!

> I read it somewhere but I can't remember where. Maybe in the stackoverflow answer we're discussing here? :-)

Post by hetman » Mon, Jan 08, 2018, 11:35 PM UTC

logiclion wrote: post #10

ktpsns wrote: post #2

I don't want to be offensive, but this is just another example where anglo-american standards for time and length measurements are ill-defined and lead to confusion. Instead, we have the SI system for the rest of the world and we have international standards for counting time -- with time going from 00:00:00 to 24:59:59 a day. I wonder why people refrain to adopt a working system in favour of culture. I never underst…

but when should 23:59:59.9999999 switch to 00:00:00?

Post by barbs » Mon, Jan 08, 2018, 11:38 PM UTC

mywittyname wrote: post #17

FabHK wrote: post #5

I thought continuity provides an answer: 11:59:59.9999999999 is still AM. 12:00:00.0000000001 is clearly PM. When should the AM switch to PM? My intuition says at the same time that the 11 switches to a 12 (and all the 9's switch to 0's). Thus, noon is pm. Having said that, in reality the solution is banish the abominable 12 hour clock, and use the 24 hour clock. That also removes the ambiguity whether "Midnight on J…

Well, since 9.9999999... = 10 [0], then 50 + 9.999999... = 50 + 10 Given that, to you claim, 11:59.59.99999[...] is still AM, then 11:59:60 is still AM, thus 12:00:00 is still AM. [0] https://www.youtube.com/watch?v=SDtFBSjNmm0 /s

Post by FabHK » Mon, Jan 08, 2018, 11:43 PM UTC

SllX wrote: post #36

FabHK wrote: post #28

Earlier quoted context omitted.

It is, when it's attached to a day - it could be at the very beginning of that day or the very end.

Friday Midnight is the same as Midnight Saturday Morning. I mean there is no standards committee for this, but that's what common convention tells us in the Anglophone part of the world.