8 ms·
Why is 11 am and 1 hour == 12:00 pm?
- ktpsns 9y agoI 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.
- merb 9y ago> 00:00:00 to 24:59:59 thats a damn long day. my day is only from 00:00:00 to 23:59:59. where do you live that you have 25 hour days? /s
- rdruxn 9y agoThat would be 25 hours in a day
- Finnucane 9y agoSometimes I miss the home planet too.
- logiclion 9y agobut when should 23:59:59.9999999 switch to 00:00:00?
- hetman 9y agoEasy, 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.
- Symbiote 9y ago> 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.)
- FabHK 9y agoWikipedia: "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." https://en.wikipedia.org/wiki/Metrication https://en.wikipedia.org/wiki/Metrication
- JacobJans 9y agoFormal 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?
- merb 9y agowell 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.
- hetman 9y agoThe 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.
- nkkollaw 9y ago> with time going from 00:00:00 to 24:59:59 a day I guess the 24-hour system leads to confusion, too..? ;-)
- FabHK 9y agoI 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 January 1st 2017" means 2017-01-01 00:00 or 2017-01-01 24:00 == 2017-01-02 00:00.
- Finnucane 9y agoBut 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.
- beambot 9y agoEven 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.
- ljm 9y agoMeasuring 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.
- deadbunny 9y agoWhat? The 24hour clock has nothing to do with timezones. 11:00 is the same as 11am and 21:00 is the same as 9pm whatever your timezone.
- coldtea 9y ago>But whose 24 hour clock? Should we all be on GMT? That's arbitrary and eurocentric. Doesn't matter. Anything would be arbitrary. Just pick one and be done with it, and we already have GMT and UTC.
- makecheck 9y agoYou’ll probably never see a flight or a movie or something start right at 12:00; it’s just so much clearer at a glance to see that 11:55 AM/PM.
- mc32 9y agoBut special sales at stores and online do begin at midnight. Say new playstation, iPhone, Xbox, etc.
- marsrover 9y agoWell, it's not ambiguous what the word "midnight" means.
- FabHK 9y agoIt is, when it's attached to a day - it could be at the very beginning of that day or the very end.
- deleted 9y ago[deleted]
- SllX 9y agoFriday 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.
- frandroid 9y agoWhen 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!
- DiThi 9y agoIt'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.
- kbutler 9y agoThe 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.
- AnimalMuppet 9y agoNo 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.
- icedchai 9y agoActually, 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!"
- Dylan16807 9y ago> 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.
- kbutler 9y agoIf it were just 11am 12am 1pm That would make sense. But it would be 11:59:59.9999999999am 12:00:00.0000000000am 12:00:00.0000000001pm 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.
- deleted 9y ago[deleted]
- fallingfrog 9y agoThis has always been a pet peeve of mine. Makes it really hard to answer simple questions like, how many hours pass between 11am and 12am?
- romanovtexas 9y agoFascinating. I've seen that at a lot of shops and places in Japan they go beyond the 24 hours – indicating continuity in a way. For example of a shop is open in the pattern – Monday, January 8th 21:00 till Tuesday, January 9th 02:00 The Japanese signboards will denote it as - Open on Monday, 8th Jan 21:00-26:00 I think it's we quite convenient and let's the people know that the shop's time pattern sort of carries on from the previous day onto the next.