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!
That's just a cop-out. If you change the question from 11 AM to 11:01 AM it's still just as valid, and there's no need to argue about the ambiguity. Is there anybody who would seriously argue that 12:00 AM plus one minute should be 12:01 PM? That way lies madness.
12:00 isn't AM or PM. It straddles them, and isn't wholly either one because of it. That's what this is about. Some people could argue that noon is 12AM. Others can argue that it's 12PM. Both views have merit, and despite that, we need to agree on one or the other, because times are often written down and everyone needs to know what time is meant when someone writes "12AM." Since consensus on this has never been achieved, we just decided on something that people COULD agree on: noon and midnight.
The question isn't valid for 11AM vs 11:01AM, because crossing into 11:01AM doesn't put you into the afternoon like 12:01PM does. It's only a valid question at the transition time between AM and PM or vice versa. So, it was decided a LONG time ago to just skip the problem and say "twelve noon" or "midnight" (or "twelve midnight".)
12:00 noon is neither AM nor PM, and there'se no confusion.
The real question is why is the hour after midnight 12:01-12:59 AM.
Anyway, the real answer is that 0/12 and 13/1 are partial branch cuts and that "12" is used because "0" is awkward for mundane reasons, but retains some of its "0-ness"
I'm not disagreeing that "noon" or "midnight" are less confusing, I'm simply saying there shouldn't be any ambiguity about 12AM or 12PM in the first place.
Any potential for confusion results from an ancient decision to designate noon/midnight as 12:00. If they had simply made them 1:00 instead then there'd be no trouble today.
Well, while the numbers of nines is finite, it's still AM.
I'm arguing for switching the very moment the number of nines is infinite, or, in other words, they've turned into (an equally infinite number of) zeros.
But whose 24 hour clock? Should we all be on GMT? That's arbitrary and eurocentric. And let's get rid of those pesky arbitrary time zones too. We should all be able to have our own personal time zones.
The one from your current timezone, obviously. And if you omit your timezone, you obviously mean your current timezone; the one you're residing in. If you're in Paris and you tell your kid dinner is at 6 PM then you mean local time. If your kid then comes home at 7 PM and says oh I thought you meant UK time then that's obviously your kid being a smartass. Even if you are both from UK. Why? Because it isn't practical to stick to a timezone you're not residing in.
Wether we're talking about 6 PM or 18 and 7 PM or 19 makes zero difference to your argument.
24H notation is just simpler and more practical. You don't have to resort to keyboard, it even takes up less space, and most importantly the context is less relevant ie. if AM/PM is omitted you still know what's up.
The only reason people stick to 24H notation, or imperial system for that matter, is "because we've always done it like this" ie. an argumentum ad antiquitatem. Not because it is better. Backwards compatibility comes with a price. You should always question whether the price is worth it.
I can think of one problem with the 24H system: analogue clocks like watches and churches. They use 12 hours. But when you watch that, that's communication to you as a human instead of human to human. And you know whether it is morning or evening, day or night, unless you're in a truly strange mental state.
Even if you eliminate time zones, you still end up having to do lookups whenever you're communicating across zones. E.g. "If I call my brother now from SFBA, is it normal daytime hours in Switzerland?" Knowing that right now is 15:00 GMT doesn't help answer that question.
Measuring time over 24 hours rather than 12*2 hours makes it abundantly clear what part of the day you're referring to, no matter what timezone it is. It's not about putting everyone on the same time, but describing it without ambiguity.
This is especially important in language, where in some cultures the word 'tonight' actually translates to what you'd call 'last night' in English, for example.
So long as we're being completely arbitrary without any regard whatsoever natural language sensibility, let's just convert time to a metric/decimal system.
In 1998, the Swiss watch company Swatch introduced the concept of a decimal Internet Time in which the day is divided into 1000 'beats' so that each beat is equal to 1 minute 26.4 seconds. The beats were denoted by the @ symbol, so that, for example, @250 denotes a time period equal to six hours.
Sorry if I misinterpreted your response, but do you think doing away with timezones in "normal" life would be a net gain? I think it would add way more confusion than it would eliminate. (e.g. "Let's have dinner Wednesday night" would be very confusing in some parts of the world. "Is that the Wednesday night just after Tuesday night? Or the one just before Thursday night?")
>Sorry if I misinterpreted your response, but do you think doing away with timezones in "normal" life would be a net gain? I think it would add way more confusion than it would eliminate.
It's the exact same information needed both today and after doing away with timezones.
If you're in the same place as the other person, there's no confusion at all. If everybody uses GMT, you know e.g. that diner around your parts (e.g. London) is around 19:00 (7pm). If you live in California you know that diner around your parts is around 03:00 (3am).
If you're in different countries, e.g. one is in London and the other is in California, "Let's have a Skype at around 11:00" is unambiguous -- it will be 11:00 at both your clocks.
Lastly, if you're in different countries and you want to call someone in California, and wonder whether now (11:00 GMT) is a good time, you just have to know the offset number (the sun rises there 8 hours later) which is the same as knowing the timezone.
Without timezones, it's only knowing the "part of the day" (whether it's late or dusk or sunrise time etc) in another place that requires knowing an offset (similar to knowing the timezone offset today).
All other calculations and coordination is vastly simplified.
>(e.g. "Let's have dinner Wednesday night" would be very confusing in some parts of the world. "Is that the Wednesday night just after Tuesday night? Or the one just before Thursday night?")
How is that confusing? Assuming we're talking about dinner, it would have to be dinner time in the place those people live. So, e.g. a little before or after sunset time on Wednesday. Whether that corresponds to 7pm or 2am or 12pm, people will know when it's that time where they live.
What are we trying to solve by moving the world to UTC? We can't change when the sun rises and sets, nor can we change our circadian rhythms. So what we're left with is the fact that different parts of the world do things at different times. Using timezones, we set the start, midpoint, and end of the day to common numbers. If we ditch timezones and move to UTC-everywhere, we still have timezones. They're just implicit now. And we also have the new burden of our day changing while the sun is still up.
You waive off my dinner example as if "dinner" is a rigid set time. It's not. I'm in New York and I eat dinner at 6pm sometimes. Other times I eat at 8pm. Under UTC, this means that I sometimes have dinner on Wednesday at 23:00 and other times I wait until Thursday at 01:00. Asking someone over for "dinner on Wednesday" would always be ambiguous.
Here are some other confusing examples, if the dinner one doesn't illustrate it:
(At work)
"What days do you have off this week?"
"I got Tuesday/Wednesday and Friday/Saturday off"
(At school)
"When is the paper due?"
"Tuesday"
"The class that starts on Tuesday or the
one that ends on Tuesday?"
There's a reason we have the days change when most of us are asleep. It's a lot easier. A day encapsulates a day.
We could acclimate to all of this, sure. But we'd still have timezones. It wouldn't be immediately obvious to the Londoner that 11:00 is a terrible Skype time for her California colleagues (3am). So I don't see the gain here. Dealing with time differences is a fundamental aspect of living on a ball Earth.
>We could acclimate to all of this, sure. But we'd still have timezones. It wouldn't be immediately obvious to the Londoner that 11:00 is a terrible Skype time for her California colleagues (3am)
Yeah, I addressed that though. We'd still need to know the offsets sunrise-wise or cultural-wise (e.g. 10pm is late to call in some countries, absolutely normal in others).
>So I don't see the gain here.
It's trading local time reference points (like the sun etc), for global coordination (in an increasingly interconnected and real-time planet) -- so everybody immediately knows what time X is everywhere. It's not meant to eliminate the fact that sunrise times etc are different, just to keep a stable frame of reference without timezones for time (one would still need the offsets to know whether it's night or day in place Y at time X).
>Dealing with time differences is a fundamental aspect of living on a ball Earth.
Doesn't mean there's one and only one way to deal with those though. Or that people don't spend a lot of time in the real-time, non-spherical, always-on, web too nowadays.
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 understood why culture and tradition is an argument for inexactness.
The biggest difficulty for people will be forming new habits. The military time convention is familiar but cumbersome. Saying "I'll see you at 17 hundred hours" is not as convenient as "I'll see you at 17 o'clock" or simply "I'll see you at 17". The latter two sound a bit weird (especially the last one), but they're perfectly natural in other languages so it's just a matter of figuring out how to overcome the initial unfamiliarity in a large part of the population. I for one think this would be a great thing to standardise on just like SI.
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.)
"As of 2017, seven countries formally do not use the metric system as their main standard of measurement: the United States, Myanmar, Liberia,[3] Palau, Marshall Islands, the Federated States of Micronesia, and Samoa.[4] However, both Myanmar and Liberia are reportedly essentially metric, even without official legislation."
Formal use is different that widespread consistent use, excluding the other system.
My observation, at least where I live, is that both systems are used in practice. Especially at grocery stores, where the aim seems to be intentional confusion. For example you buy oranges listed for 2.34 a pound, but at the register you are charged 5.74 a kilo. Where you charged the correct rate? Maybe? Maybe not?
well in germany you still say "ein pfund" (one pound) or "halbes pfund" (half pound) if you buy sausages/meat. but you mean 500g and not the real value of one pound. it's just that this is used because we got used to it.
we also have a wierd system for the clock where we say "viertel vor" (a quarter to) or "viertel nach" (a quarter past). which is pretty common to say the time in quarters instead of values.
Easy, 00:00:00 is one second after 23:59:59. You can use 24:00:00 in some circumstances to refer to the midnigt at the end of a day but it would be redundant say on a clock face.
When the bells of Big Ben — or any chiming clock that rings out the hours of the day — chimes with one bell, we know that the first hour has just been completed. As one commenter observes, having it ring zero bells wouldn’t tell people what time it is. You can’t go from ringing eleven bells one hour to not ringing any bells at all an hour later to then ringing one bell the hour following the one in which you failed to ring any bells at all. People wouldn’t be able to tell what time it was because of something they didn’t hear!
Imagine this dialogue:
TOM: Oh good, it’s time for lunch!
JERRY: Oh really, and how do you know that?
TOM: Because it has to be noon, since I just now didn’t hear the clock!
A while back I wrote a calendaring application where I encountered a similar problem and came up with a similar solution. If someone scheduled an all day meeting that ended at 12 midnight, the calendar would show it as a two-day meeting. The meeting started at 12AM on January 8th and ended at midnight of the same day... but since January 8th ends at 11:59PM and January 9th begins one minute later, the invite would roll over and be displayed as ending the next day. I'm not actually a real programmer (I just pretend to be one when someone wants to pay me) so this took way longer to figure out than it really should have.
I tried various things like if a meeting says 12AM, subtract one day, but then I'd encounter edge cases like meetings that start at 12AM now showing the previous day, or meetings that are scheduled from 12AM on the 8th to 12AM on the 8th (basically zero-minute durations) showing the wrong day or a bunch more things you don't think of until you try to develop applications for end users you might never talk to.
Eventually I set it to make any meeting that ended at 12AM just subtract one minute from the overall duration so it would end at 11:59PM instead. It didn't as much solve the problem as it did just avoid it, but at least people stopped complaining.
I think trains in Britain avoid being scheduled to leave at 00:00, it's easy enough to leave at 23:59 at that time. It's not busy. But 12:00 wouldn't be ambiguous, since that can't be 00:00 or 24:00.
It would be pronounced "twelve hundred hours" by the automated announcement systems, and 12 o'clock by people.
00:01 is announced as "midnight oh one". ("The train on platform nine and three quarters is the midnight oh one service to Hogsmeade, calling at Hogsmeade only. A buffet trolley of drinks and light refreshments is available on this train.")
It's not confusing for us Europeans since we use 24 hour clocks. Midnight is 00. However I did not understand the reason the 24 hour clock caught on until now. TV schedules use 24 hour clocks to avoid this ambiguity.
The instant it becomes noon, it is no longer ante meridian (before noon). Thus we have to make an arbitrary allocation, and it makes a lot more sense to lump 12:00 with 12:01-12:59, rather than with 11:00-11:59.
No it doesn't. It makes exactly the same amount of sense to put 12:00 with 12:01 as it does with 11:59, because noon is not post meridian in exactly the same way that is not ante meridian.
Actually, it does make more sense to group them. You see that 12 at the beginning of 12:00 and 12:01?
Most kids in the US are taught that 12 PM is noon and 12 AM is midnight in elementary school. Though many understand this by first grade, I have been surprised to encounter native English speaking 40+ year old adults that still do not remember this. "Meet me at lunch at 12 AM!"
> because noon is not post meridian in exactly the same way that is not ante meridian.
That was already implied. I think you're confused about what kbutler was stating. The full argument goes like this:
1. by itself, 12:00 is not post meridian
2. by itself, 12:00 is not ante meridian
3. therefore we must choose which label to use on other merits
4. without 1 or 2, it makes more sense to lump it with the time that's a single digit off by one, and not the time that's many digits off by many
---
On top of that, for 100.0000% of the time the clock reads "12:00" around noon, it's PM. Even if you defined the moment of noon to be AM, it would be impossible to ever catch a clock saying 12:00 during the final moments of AM.
So incrementing the arbitrarily least significant unit would require toggling the most significant unit with no other digits changing.
And if you ever saw a clock displaying 12am, it should actually be p.m. by the time the light reached your eye.
Makes more sense to increment the a to p at the same time you roll over all those 99s and 59s to 0, then 12 is consistent however precise your clock is.
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 January 1st 2017" means 2017-01-01 00:00 or 2017-01-01 24:00 == 2017-01-02 00:00.