Why use a 24 hour clock?!
ฝัง
- เผยแพร่เมื่อ 9 ก.พ. 2025
- Head over to my site for lots of GCSE Maths practice! mathskitchen.c...
In this video I give a brief description of how to convert to and from a 12 hour clock and a 24 hour clock. Then I get into the meat of the video - why it's useful to be able to use a 24 hour clock.
The situation I find it really useful in is if I need to find how long it is between two points in time. For example if I was working from 8am until 4pm how many hours is that? Now, clearly you can do that without using a 24 hour clock but I think it's much easier with.
Here's what I do: I convert the afternoon time into a 24 hour clock by adding 12 to it. In the above example 4pm becomes 16:00. Then i just subtract the start time from the finish time. So in the above example I would do 16-8 which is 8. So from 8am until 4pm is 8 hours.
Thanks for watching!
James
Ever sense I was 12 years old, I used the 24 hour time. It's way simpler, removes confusion, and is cleaner
2:00 I'll go a step further and say converting time to decimal hours makes figuring time easier (more on that further down.) 9:00pm - 6:30am = 14hrs and 30min OR since most calculators can't do this: 21 - 6.5 = 14.5hrs
For mathematical purposes, a mental 48hr clock also comes in handy.
0400 = 2900
Start 1900 end at 0400
Convert 0400 to 2900
29-19 = 10hr.
I started this comment mentioning a decimal clock. "What's a decimal clock?" You might ask...
It's kinda like the metric version of a regular hour. There is 100 decimal minutes in a decimal hour. There might be some of you that can recall old-fashioned time clocks that recorded time this way. (Example 6:30pm = 18.50 or 18 50). The best way to use the decimal clock is to reduce the increments from 100 to 20 rounding to multiples of 3 minute intervals.
You might say: "That sounds complicated!"
SOUNDS COMPLICATED? What if I demonstrated that it's just a matter of what you're used to and that decimal hours is actually EASIER?
Conventional ⏰ math: 54min + 6min = 1hr
Try putting 54+6 in your calculator and see if it equals 1. Not exactly easy in practice once you think about it.
Decimal math with the EXACT SAME PROBLEM: 0.9hrs + 0.1hrs= 1hr.
To do it in your head start from known decimals of 15min (.25), 30min (.5), 45min (.75) and work your way up or down. 3min = .05 and 6min = .1
Addition method: 18min = .3
(HEAD MATH: 15min + 3min = 18min >>> .25 + .05 = .3hrs)
Subtraction method: 24min = .4 (HEAD MATH: 30min - 6min =24min >>> 0.5 - 0.1 = .4hrs)
Minutes/hours
03 = .05
06 = .1
09 = .15
12 = .2
15 = .25
18 = .3
21 = .35
24 = .4
27 = .45
30 = .5
33 = .55
36 = .6
39 = .65
42 = .7
45 = .75
48 = .8
51 = .85
54 = .9
57 = .95
Usually I can ignore am and pm but in the rare case I need it I can't figure it out.
@@Stacy_Smith dafuck
Same with me because I used my date and time to hack my offline games and I turned my iPad time to 24 hour time because it’s more convenient and now I prefer it
Huh
From mainland Europe, I do not know anyone who does not uses the 24 Hour clock. Trains, airplanes, buses, schools, universities, etc
and all individuals.
Interesting eh? I'm with the mainland Europeans on this one...and the metric system!
Despite this video, here in the UK, train & plane timetables and departures, boarding passes, times shown on pc, laptops, mobile phones, TV and iPhone weather is all in 24 hour clock. This video perhaps gives the impression we don't use it in the UK, but we most certainly do.
2:00 I'll go a step further and say converting time to decimal hours makes figuring time easier (more on that further down.) 9:00pm - 6:30am = 14hrs and 30min OR since most calculators can't do this: 21 - 6.5 = 14.5hrs
For mathematical purposes, a mental 48hr clock also comes in handy.
0400 = 2900
Start 1900 end at 0400
Convert 0400 to 2900
29-19 = 10hr.
I started this comment mentioning a decimal clock. "What's a decimal clock?" You might ask...
It's kinda like the metric version of a regular hour. There is 100 decimal minutes in a decimal hour. There might be some of you that can recall old-fashioned time clocks that recorded time this way. (Example 6:30pm = 18.50 or 18 50). The best way to use the decimal clock is to reduce the increments from 100 to 20 rounding to multiples of 3 minute intervals.
You might say: "That sounds complicated!"
SOUNDS COMPLICATED? What if I demonstrated that it's just a matter of what you're used to and that decimal hours is actually EASIER?
Conventional ⏰ math: 54min + 6min = 1hr
Try putting 54+6 in your calculator and see if it equals 1. Not exactly easy in practice once you think about it.
Decimal math with the EXACT SAME PROBLEM: 0.9hrs + 0.1hrs= 1hr.
To do it in your head start from known decimals of 15min (.25), 30min (.5), 45min (.75) and work your way up or down. 3min = .05 and 6min = .1
Addition method: 18min = .3
(HEAD MATH: 15min + 3min = 18min >>> .25 + .05 = .3hrs)
Subtraction method: 24min = .4 (HEAD MATH: 30min - 6min =24min >>> 0.5 - 0.1 = .4hrs)
Minutes/hours
03 = .05
06 = .1
09 = .15
12 = .2
15 = .25
18 = .3
21 = .35
24 = .4
27 = .45
30 = .5
33 = .55
36 = .6
39 = .65
42 = .7
45 = .75
48 = .8
51 = .85
54 = .9
57 = .95
Yes but what a lot of people who use the 12h clock don’t realise is that we write 14:00, but say 2 o’clock out loud and not 1400 hours
As an American who uses the 12 h clock, I always thought it was weird using the 24 hour, but now that I've learned the 24 hour clock, I've concluded that we are actually the weird ones.
The cool thing about using a 24 hour clock is that I actually read 14 as two, 18 as six, 22 as ten, etc. when reading a clock. So it isn't inconvenient in that aspect at all, there are only upsides. Especially in an international/day routine context (watch the beginning CGP Grey's 72 hrs in Las Vegas to understand the confusion!). I remember "am" and "pm" as "after moon" and "p/before moon", so you can understand how that can become confusing for me. It would have been easier the other way around with "midday" instead of "moon". Though I bet if you grew up with it it wouldn't be a problem.
Am and pm are ante meridiem and post meridiem. And meridiem is midday.
Ante = before, post = after
exactly, the moment you can instantly say that 2 is 14, 6 is 18 etc it becomes so much immediate.
I know but I can never remember, I will try though. Post meridiem shouldn't be too hard though. Also I just realised how BS my moon trick is since the moon is visible as much in the day as at night. 🤣
I started using 24 hour time at the beginning of the year. It's so much better than 12 hour time because it's convenient.
I live in America and I use 24 hour time, Celsius, and metric (for most things) and it pisses people off to no end
2:00 I'll go a step further and say converting time to decimal hours makes figuring time easier (more on that further down.) 9:00pm - 6:30am = 14hrs and 30min OR since most calculators can't do this: 21 - 6.5 = 14.5hrs
For mathematical purposes, a mental 48hr clock also comes in handy.
0400 = 2900
Start 1900 end at 0400
Convert 0400 to 2900
29-19 = 10hr.
I started this comment mentioning a decimal clock. "What's a decimal clock?" You might ask...
It's kinda like the metric version of a regular hour. There is 100 decimal minutes in a decimal hour. There might be some of you that can recall old-fashioned time clocks that recorded time this way. (Example 6:30pm = 18.50 or 18 50). The best way to use the decimal clock is to reduce the increments from 100 to 20 rounding to multiples of 3 minute intervals.
You might say: "That sounds complicated!"
SOUNDS COMPLICATED? What if I demonstrated that it's just a matter of what you're used to and that decimal hours is actually EASIER?
Conventional ⏰ math: 54min + 6min = 1hr
Try putting 54+6 in your calculator and see if it equals 1. Not exactly easy in practice once you think about it.
Decimal math with the EXACT SAME PROBLEM: 0.9hrs + 0.1hrs= 1hr.
To do it in your head start from known decimals of 15min (.25), 30min (.5), 45min (.75) and work your way up or down. 3min = .05 and 6min = .1
Addition method: 18min = .3
(HEAD MATH: 15min + 3min = 18min >>> .25 + .05 = .3hrs)
Subtraction method: 24min = .4 (HEAD MATH: 30min - 6min =24min >>> 0.5 - 0.1 = .4hrs)
Minutes/hours
03 = .05
06 = .1
09 = .15
12 = .2
15 = .25
18 = .3
21 = .35
24 = .4
27 = .45
30 = .5
33 = .55
36 = .6
39 = .65
42 = .7
45 = .75
48 = .8
51 = .85
54 = .9
57 = .95
12 hour clock (AM/PM) on electronic devices is overrated lol
@@Stacy_Smithsorry bro 12 > 10
Th 24 hour clock is much much easier and better than the 12 weirdo
in Brazil we use 24 hour clock for general purposes and 12 hour clock for conversation
I’m from India and currently in the United States, I once fell asleep at 4:30 PM and woke up at 5:30 PM, but the moment I thought it was 5:30 AM since my cellphone doesn’t show am and PM, so I just started using 24 hour clock on my phone to avoid confusion 😂
I used to panick when that would happen to me. Ever since I switched to 24 time it hasn’t happened.
I think in the US they refer 24-hour clock as "military" because only their military uses it, but for the rest of the world its just 24-hour time. Correct me if I'm wrong someone.
Yes, but the military system is honestly really stupid. For some reason they transcribe their hours as hard, big numbers, for example 2152, instead of how we do it. That lack of the colon makes it look ridiculous.
still better than 12h AM/PM
Hospitals also use the 24 hr system which it is its proper name.
I am shocked to see a lot of people dont know 24h format. I had to learn it in kindergarden and tell the teacher all the times.
It isn’t taught at all in the United States
the kid is just rolling at 00:24
I'm a x military officer and i have used the twenty four hour clock for the majority of my life, i find it easier to use than the anti meridian AM and post meridian PM twelve hour clock. it is easier to use and their is no error made by anyone what time to meet say one o'clock but they then need to know morning of night. saying 1300 is much easier and quicker to pass on.
To me as a german it is shocking how people get confused with this...
I changed ALL my devices (phone, PC, car clock, tablet, arm watch, even dashcam) to 24 hours. It helps avoid confusion with alarms and appointments even if they use the am/pm system here.
I know that Indonesia uses the 24 hour clock with schedules. It is very convenient to avoid having to write AM or PM.
Thank you for this great and concise explanation! I learned quite a bit and have acquired a new way to convert from 12-hour to 24-hour time.
I never thought of it this way 😅. I’m switching to a 24 hour clock right now!
I've been using 24 hour time for several years now and I never ever want to go back to 12 hour format!
I keep on rolling like the kid in the background
I live in Canada so we mainly use the 12hour clock. I easily understand how 24 clocks work, but I prefer the 12 hour clock because it makes the day feel shorter by splitting it into two sections rather than one LONG day. It’s weird, but I guess that’s just me.
Me too bro from India 🇮🇳🇮🇳🇮🇳
I view it as split into two sections with 24-hour time where 12 is still the middle it just doesn't reset the numbers.
Not sure why i use it but an easy way to work it out for beginners is minus 2 at the second number. So 19.00 minus 2 is 7. 7pm. 15.00 minus 2 is 3. 3pm
1:40 It's a little bit of a bad example, bc 9-3=6, but that's just coincidence. 9am to 4 pm doesn't give you 7hrs (9-4=5)
It’s just easier. Just call the hours by their name. Imagine you have 24 children… would you give them 24 individual names, or only 12 with the addition of am and pm?
The best on the 24 hour system is, you can see immediately, if it’s the same day or the next day: 24 o clock is this day, 00 o clock is the next day… that’s important for legal issues, contracts etc. For example: this contract Beginns at 1st of November, 00.00 hrs and ends on 30th of November 24.00 hrs… got it?
You should use 00:00 on both, honestly.
the thought of naming a child 12 am made me chuckle.
that made my day. :^)
I worked for the MOD & an airline for nearly 40 years & we always went by the 24hour clock so I still do..
24h clock or bust. Stock standard way to represent time.
“Erm, is that oh six hundred... in the morning?!” A Few Good Men
0600
Today is my 1st day using the 24 hour time and it makes the day seem like it’s going slower
😂I know
I’ve seen 13 at the six o clock position… and 1-24 on the dial… that is what I’m here for
It depends if you learn it as an adult or as a kid, as a European I grew up with it so it is very natural for me, as others say, when I see 14:25 I know it is 2:25 PM, if it is 18:35, IT IS 6:35 PM, I do not even need to count anything, comes naturally as a language
I started using 24hr time on an iPhone 2G and have ever since. After a while it becomes second nature.
I just learned this, and WOW! I'm REALLY getting the hang of it! 😎😁
Im used to 24 hour clock its way easier
No it's not.
@@HMenendez F'course it is. Not only is it easier for calculating time but you also don't have to remember what am and pm are if you're not using the 12 hour format on a regular basis. You have to actively teach someone which one is for the first half of the day and which one's for the second half. And since am and pm are both based on Latin there isn't really a linguistical mnemonic that you can memorize unless you make up your own (like I did, like when I'm unsure what is what I translate pm to _past noon/midday_ but that's just me) but you don't have that with the 24 hour format. Any human being that isn't a complete imbecile can understand that, for example, 14 o' clock always refers to the last half of a day which isn't guaranteed when using the 12 hour format.
@uday singh Apparently anyone who watched this video cares wether or not 24 hours is a good/better time format...
@uday singh And I don't remember my first comment being addressed to you... also you might want to check your brain because you very much asked me a question in your previous reply
_lol_
@@HMenendezYeah, of course the guy who doesn't know it has to share his invaluable opinion lol
Lolol look at the kids in the background
2:00 I'll go a step further and say converting time to decimal hours makes figuring time easier (more on that further down.) 9:00pm - 6:30am = 14hrs and 30min OR since most calculators can't do this: 21 - 6.5 = 14.5hrs
For mathematical purposes, a mental 48hr clock also comes in handy.
0400 = 2900
Start 1900 end at 0400
Convert 0400 to 2900
29-19 = 10hr.
I started this comment mentioning a decimal clock. "What's a decimal clock?" You might ask...
It's kinda like the metric version of a regular hour. There is 100 decimal minutes in a decimal hour (1 decimal minute = 36 seconds). There might be some of you that can recall old-fashioned time clocks that recorded time this way. (Example 6:30pm = 18.50 or 18 50). The best way to use the decimal clock is to reduce the increments from 100 to 20 rounding to multiples of 3 minute intervals.
You might say: "That sounds complicated!"
SOUNDS COMPLICATED? What if I demonstrated that it's just a matter of what you're used to and that decimal hours is actually EASIER?
Conventional ⏰ math: 54min + 6min = 1hr
Try putting 54+6 in your calculator and see if it equals 1. Not exactly easy in practice once you think about it.
Decimal math with the EXACT SAME PROBLEM: 0.9hrs + 0.1hrs= 1hr.
To do it in your head start from known decimals of 15min (.25), 30min (.5), 45min (.75) and work your way up or down. 3min = .05 and 6min = .1
Addition method: 18min = .3
(HEAD MATH: 15min + 3min = 18min >>> .25 + .05 = .3hrs)
Subtraction method: 24min = .4 (HEAD MATH: 30min - 6min =24min >>> 0.5 - 0.1 = .4hrs)
Minutes/hours
03 = .05
06 = .1
09 = .15
12 = .2
15 = .25
18 = .3
21 = .35
24 = .4
27 = .45
30 = .5
33 = .55
36 = .6
39 = .65
42 = .7
45 = .75
48 = .8
51 = .85
54 = .9
57 = .95
Thank you for the comment, Stacy! I often use 'decimal' time too but must admit have never taken it to the level you are describing here! Love it.
@@MathsKitchen You're welcome. TIME IS MONEY, I drive for a living; so figuring ETAs and availability times on the fly is a huge part of what I do.
For safety and practical reasons doing most of the math in my head rather than a calculator is easier.
On TH-cam there is a lot of videos explaining AM/PM...why..? cos its so stupid and confusing. There is hardly any explaining 24H clock, why? Cos it works and create no confusion...!
exactly!
been using this for past 3 years.
it is less confusing than am and pm for me.
how about a 48 hour clock?
Finally the best and most succinct explanation for the collapse of the British Empire.
He He
It's global known if you can count to 24.
It's the transition between am and pm that it tricky for most people; For the 0.02% of the civilized world that even bother to learn it.
I always understood military time by subtracting 2 and understanding we have 24 hours in a day.
So 23 - 2 = 21, the 1 makes it 11pm (the 2 just represents the 2nd digit while 1 represents single digits)
14 - 2 = 12, so 2pm.
21 - 2 = 19, so 9pm.
Thanks 😊
No problem 😊
I am a American Volunteer firefighter. We use the military time to avoid ambiguity. For example we have to log our calls. It's important for us to be accurate as possible.
Just take 2 off the end number and what that makes is what the time is.
Why use 24h? For the same reason to use metric and IS for measure...
How do you use it in conversation? Do you say 14 hundred for 2pm? Do you see 14 hundred and 10 for 2:10pm? Or just 14? Or 14 o'clock? Do you say 1420 oclock? This is what I don't understand.. I know how to convert the times but how do you actually say it in conversation?
in conversations i just say half past 7 or something
@Geek37 Thanks, how would you say for example, 14:10, 14:15?
Usually people just use 12 hours for conversation, as in "let's have a party at four"
alternatively, you can
say the hour then the minute
"Oh what time exactly"
"something like fourteen twenty I guess"
"my guy I have to go to a funeral that day"
I know them both on the fly
Using it since 2015, never changed it back.
Used 12-hour format before. Now 24-hour format.
Yes!
That help thx 😊
I use Military time from 2022.
been using 24 hour time all my life but I still use my fingers :(
I started using it just to be different
LOL
However I usually made mistakes setting up my alarm by mistakenly turning it to pm instead of am which hasn't been an issue since I switched.
It's just easy to know how much time you have left in 1 day out of 24 hours so let's say it's 20:00 then fuk you have just 4 hours left so do your work asap
Europeans use the 24 hour clock
bro, i've been counting time like a fucking idiot.
I'm watching this at 00:03
12:03AM 🤪
17:48
20:05
19:31
23:51
FACT Also known as army time
this am/pm nonsense makes no sense whatsoever
Hi, this is random, but..
Could you please confirm the name of the place you were filming?
It sounded like you said Stockwood, on the edge of Exeter?
I searched Stockwood and can not find it near Exeter, only near Bristol.
I ask because I’m travelling in the UK next week and that location looks LUSH 😍 so I’d really like to visit it.
Hoping that you see this and can respond!
Also, I love 24 hour time and find 12 hour time to be silly. Which is why I clicked on this video to begin with 😅
Hi, its a really nice piece of woodland called Stoke Woods. However, it's very small - not really worth travelling to! If you're in the UK you'll be able to find much better examples close to wherever you are. Hope you enjoy your visit!
Everyone in Europe is using 24 hour system, however none of the analog watche that have 24-hour dials have the noon on top to make it more intuitive. The sun doesn't rise at midnight.
interesting. I actually always prefer 24 analog watches with midnight on top over noon. Never thinking about the hour hand copying the sun 'trajectory'. Just the reset of hours counting and begining of a new day...
hi
Hi
Is this guy teaching us how to count from 0 to 24?
Evidently Americans have a problem with that
@@Mroquelle true
Most of North America uses the 12 hour clock.
_._
Hi
The 24 hour clock sounds so dehumanizing which is why it was used in 1984.
It actually takes longer to count in 24 hour clock
12 hours x2 is 12 hours x2. It's the same amount of hours just named differently. But you know what's good about 24 hours? You don't have to count at all since it's easier to just calculate everything in your head.
12 hour clock best
I will make 100 hour clock.😁😁
if I try to use the 24 hour clock I have to do a calculation to figure out what time it is.
ex: if someone says, "Meet me at Tim's house at 2100 hours." I have to do math: 24-21=3. 12-3=9. So it's 9pm.
Now if they just said 9pm to begin with I'd know instantly and not have to do math.
Why do all the math when you can just visualize a clock and have the answer in seconds.
Sorry, but 12 hour clock time sucks
exactly!
I hate military time. I’m not in the army
This isn't military time genius.
I hate it
What this guy is talking about is useless
Then perhaps the two of you have something in common?