12 hour time format
Time formats. Tishuk and I were arguing about whether “1645″ or “445p” is clearer, so I got to doing a bit of research on the 12 hour vs. 24 hour thing. We uncouth folks here in the US of A use the 12 hour system, of course, while the rest of the wacky world likes 24. But which is better?
Well despite the bleating from those metric sissies across the Atlantic, I’m here tonight to tell you one thing and one thing only: the 12 hour time format beats the piss out of the 24 hour time format. And I’m going to tell you why by quoting the arguments of a holier-than-thou German guy who has some really popular web page on time standards. And then I’m going to rebuff each one of his points. While I’m doing this, I’m also going to make fun of him.
Arguments for 24 hour time, rebutted
Markus Kuhn is evidently interested in a lot of things, but one of them is time formats. He’s quite passionate about the superiority of the 24 hour system over the 12 hour system. I’m not going down without a fight. My comments are the snarky ones with the black background..
ul li ul li { background-color: black; color: #eee; padding: 3px; }
The old English 12h notation has many disadvantages like:
- It is longer than the normal 24h notation.
- Is it? When the hour is in the double digits, you’re right. But when it’s 1:15pm, you can only write that time as 13:15. The American Way™ can go for 1:15, 1:15p, or 1:15 p.m.—pick your poison, Eurohype.
- It takes somewhat more time for humans to compare two times in 12h notation.
- Hey hey, not so fast, cowboy! How’s it faster to make the 03:30/22:15 comparison than it is to make the 3:30a/10:15p comparison? What am I missing here?
- It is not clear, how 00:00, 12:00 and 24:00 are represented. Even encyclopedias and style manuals contain contradicting descriptions and a common quick fix seems to be to avoid “12:00 a.m./p.m.” altogether and write “noon”, “midnight”, or “12:01 a.m./p.m.” instead, although the word “midnight” still does not distinguish between 00:00 and 24:00 (midnight at the start or end of a given day).
- Interesting. You say “the word ‘midnight’ still does not distinguish between 00:00 and 24:00.” That would be an interesting point—if 24:00 existed! Care to continue this argument on, oh, September 31st?
- It makes people often believe that the next day starts at the overflow from “12:59 a.m.” to “1:00 a.m.”, which is a common problem not only when people try to program the timer of VCRs shortly after
midnight.
- VCRs? Pshaw! Welcome to the TiVo age, Herr Kuhn!
- It is not easily comparable with a string compare operation.
Since most computer programs will store the time in 24 hour format, this is a silly point. “If computers use 24 hour time, why don’t we?” you say. First off, because I said so, and that’s really the most important thing here.
Secondly, how computers store information (and how programmers think) is of extremely little relevance to this debate. (Yes, by the way, it’s a “debate,” even if Markus doesn’t know we’re having it and doesn’t know who I am.) To translate a 24h date to 12h format, on-the-fly, is trivial. Computers perform this “translation” for ASCII characters; would you suggest that we speak in 1’s and 0’s?
- It is not immediately clear for the unaware, whether the time between “12:00 a.m./p.m.” and “1:00 a.m./p.m.” starts at 00:00 or at 12:00, i.e. the English 12h notation is more difficult to understand.
- i.e. This sentence is more difficult to understand, jeez. Anyway, as long as we’re designing a system for the “unaware,” how about I gather up dog poop from around the neighborhood and put it in a bag marked “Do Not Eat.” I mean, someone might be unaware.
Please consider the 12h time to be a relic from the dark ages when Roman numerals were used, the number zero had not yet been invented and analog clocks were the only known form of displaying a time. Please avoid using it today, especially in technical applications! Even in the U.S., the widely respected Chicago Manual of Style now recommends using the international standard time
notation in publications.Okay, so this is the paragraph that really pissed me off. I just recently visited Deutschland, Herr Kuhn, and I can tell you that I spotted more than a couple of “dark age relics” there: analog clocks which display 12 hour time. For half of the day, these clocks display the wrong time; I have to do a calculation in my head to fix the time. When that clock says “4:45″ and I’m in Euroland, that’s the wrong time. I have to make it 16:45. So I think it’s time for you to go on a crusade to fix up those clocks and get them in line with your obviously superior 24 hour system. I mean, since your reasons above are obviously bulletproof.
Oh, and Markus: are you sure the Chicago Manual of Style is so well respected?
July 25th, 2005 at 11:06 am
I read your little article here and loved it. I’m currently spending my holidays in the beautiful Canada and love the 12h system. Sadly, in reality, I reside in Germany where everyone favours the 24h system. When I tell someone I’ll meet them at 10 (obviously referring to the evening as that is when the party was to begin) they do not comply. They need to be told 22 o’clock, which sounds stupid in English, not necessarily in German since it’s so common. And honestly, who seriously wants to use the 24h system? The Army, and well, computers, otherwise they couldn’t calculate it efficiently. I don’t know why people have to simplify the simplest things. Who cares when midnight is? He afraid of ghosts or something. Most people sleep at midnight so who cares? And thise that don’t sleep are probably drunk or getting some. Geezus this guy needs a beating, looks like an idiot too.
Nice article.
July 26th, 2005 at 10:26 am
12? 24? Screw ‘em both I say. Redefine seconds, minutes, and hours so that each day has 10 hours, each hour has 100 minutes, and each minute has 100 seconds.
July 26th, 2005 at 12:21 pm
I can see the benefits of the 24h system, but after discussing it with Tom for way too long, I think from here on out I shall be dropping the colon, and the “m” in “am” and “pm.”
I’m disappointed Tom didn’t mention the marketablity of the 445p convention, so I’ll do my best… Since Americans aren’t going to immediately know what 1645 is, it’s a smoother comprimise to go with 445p. There is a level of innefficiency in the 12h method. For instance, to represent the tops of all the hours (1:00, 2:00, etc), the 12h “445p method” requires 102 characters, whereas the straight 24h method only requires 87 characters. 15% better. Therefore, “It is longer than the normal 24h notation.” is accurate on all counts. (Sorry Tom–correct me if I’m wrong). But, in my mind, the probable acceptability of the 445p convention in America is too strong to get beaten by a mere 15% efficiency increase. (think about the qwerty keyboard). We [Americans] can phase-in 24h clocks in thirty years or so and the “Nobrainer Method” in sixty years or so. Wow, this is going to be an exciting century.
Nobrainer, you proposal would add 3.8 hours onto the day. We’d have to redefine what a “second” is if we did that. Not a bad idea if it were put in place back when a sweeping change like that could have been made with little or no popular uproar. Hindsight is always 6/6 (meters). Eitherway, I say we do it ASAP.
I also think we should stop using months and days. Just go with a number between 0 and 364.25. We’re on day 205 this year my friends. So it’s 2005:205:119p in my world. Eat it.
Your moment of Zen:
“Anyway, as long as we’re designing a system for the ‘unaware,’ how about I gather up dog poop from around the neighborhood and put it in a bag marked ‘Do Not Eat.’ I mean, someone might be unaware.”
July 26th, 2005 at 12:31 pm
Why this topic turns you so angry? Here in Italy we use both systems but more likely the 12h one because easier and without mistakes… Each time I read about an hipotetic superiority of something or someone I smile…
This topic remember me when at school teachers tried to learn us the IUPAC notation for chemical terms… Try to buy something calling it with a IUPAC notation in a shop ;-) Or better a Megagram of meat ehehe. Standard is what people make it a standard and not something told by 100 hot brain-man…
For german friends (as Jesus): I would like to give a tip… it’s sufficient to add these words “in the morning, in the afternoon, in the evening” and you will be free to use the 12h system even in the German nation!!! It seems a miracle, tell me if it works ;-P…
July 26th, 2005 at 4:44 pm
Tom: 1
Markus: 0
September 29th, 2005 at 5:58 am
Dear all, pro and con
I ended up on this page as I - as a European, having been taught the 24h system all my life - was trying to find out what time of day it would be if an US clock would say 12:00 am. Would it be dark outside (provided this clock would not be on yonder side of any arctic circle in the midst of July) of would it be the midst of day (provided blablabla the opposite side of ths globe we live on)?
Basically, the word “meridiem” (commonly abbreviated to ‘m’ in time notation) means ‘midday’. At least it did when I learnt my Latin in good old grammar school. So midnight would be BOTH 12am AND 12 pm, as midnight is twelve hours removed from midday, whichever way you go. So calling midnight 12:00am is just as defendable as 12:00pm. And this is where the ambiguity starts.
Had you decided to call midday 12 and midnight 12N, it would make sense.
After all, at midnight you say it is 12 hours before midday, but at 1 (in the morning, as you call it, while we say 1 at night) it is NOT 1 hour before midday, but 11 hours. Funny isn’t it: counting 11:29p, 12:00a, …, 12:59a, 1:00a … It gets more, and then less again.
I am confused, and hope you will soon learn to count beyond twelve. And lose those funny thumbwidths and shoesize 8 that you use to measure distances. And forget those gallons, that even manage to differ from the Imperial ones they were derived from. Basically: learn that there is more world beyond the US borders than within.
(Sorry: I intended to write an objective argumentative note, but somehow I seem to have digressed. How could that have happened ? )
By the way: in common all day parlance, eleven in the evening is pronounced eleven o’clock, but written as 23:00. It is ever so simple …
-t-
October 16th, 2005 at 10:39 pm
Some people just don’t get it.
March 19th, 2006 at 5:31 pm
It may be true that you are more familiar with the 12 hour notation, but that’s your personal impression and not an argument. And don’t insult (that’s what you DID) other people, just because you don’t agree with them.
May 1st, 2006 at 5:01 am
I found this page because I searched for 12AM.
When is that? Midday or midnight?
12 Hour format sucks major.
The only thing I learnt on this page is that Americans don’t want to change anything. They are the masters of universe. Every Inch and Yard.
How much is a cubic inch in cubic feet, or how many cubic feet is there in a cubic mile.
If anything is wrong, change it.
May 1st, 2006 at 11:27 am
That’s Masters of the Universe, capitalized.
June 1st, 2006 at 12:08 pm
hi, can you recomend any sites that help with the time?
it’s just that i’m strugling to tell the time and i’m in year seven!
i find it really hard and get embarresed!
April 9th, 2008 at 3:18 pm
The military, police, and many companies have good reason to use the 24-hour format. Their activities can occur at any time, even when most American civilians would not usually expect such events.
The companies and agencies that use the 24-hour format are active 24 hours a day. The 12-hour format is adequate for people who keep traditional business hours. The USA is using a time format from the 12th-14th centuries, which was adequate then, as very few people were awake at night. The introduction of electric lighting makes it possible to work at night, as I usually do.
April 9th, 2008 at 3:38 pm
Most digital clocks and watches do switch from 12h to 24h. Analog clocks do not have this ability. Midnight and noon are much clearer than 12:00 AM and 12:00 PM.
The idea that Nobrainer has about having 10-hour days of 100 minutes each was tried during the French Revolution. It did not catch on the way the rest of the metric system did. It would make our wages easier to calculate.The 12-hour format was intended to accommodate analog clocks, which are still very common. The 24-hour format would not look well on an analog clock, but perfectly acceptable on a digital. While we are at it, the whole world could be on UTC, which would make global transactions easier. The U.S. time zones are the product of the railroads, the fastest transportation then available. It still serves us quite well domestically, but may trip us up globally.