# How to write lengths of time in a short way with numbers

I am writing statistics results and I want to put a list of lengths of time.

In decimal values it will be, for example, `1.90 hours` but this is not very human friendly.

Then I think I can use `1 hour and 54 minutes` but it is very long and difficult to compare with other lengths of time.

I would like to have something like: `1:54` but I don't know how to express the units. Would it be `1:54 hours` or would it be `1:54 minutes`? both feel wrong.

• fairly typical is 1h54m
– JMP
Mar 29, 2017 at 7:31
• You could say 114 minutes. Mar 29, 2017 at 7:31
• @JonMarkPerry your suggestion sounds right, can you create an answer with it? Mar 29, 2017 at 7:32
• It also depends on your target market. For example, English speakers would probably prefer 12:34:56, whereas I believe Holland/Netherlands, prefer 12h34m56.
– Neil
Mar 29, 2017 at 16:19

The W3 standard uses:

hh:mm:ss

For simple timestamp, with no seconds, try:

1h54m

or:

01h54m

Both are readily parsed by a computer due to the h and m and indicating the end of the numeric.

• You can also put 1:45, although that's sometimes confused for "an hour and forty-five minutes after noon/midnight," depending on context. Mar 29, 2017 at 12:53
• @MissMonicaE That's the difference between "time" and "duration". They shouldn't be confused if you know what you're looking at, and anything that's meant to be one, shouldn't be labeled the other.
– user39425
Mar 29, 2017 at 22:31
• @fredsbend Right, I'm saying that hours:minutes (or minutes:seconds) notation can be used for duration as well, depending on context. For example, if I said I ran a 4:30 marathon, that means I finished in 4.5 hours, not that the race started or ended thirty minutes past four o'clock. Mar 30, 2017 at 12:05

ISO8601 (https://en.wikipedia.org/wiki/ISO_8601) has a section on periods, so things like "P1D" represents one day, or "P3Y6M4DT12H30M5S" represents a duration of "three years, six months, four days, twelve hours, thirty minutes, and five seconds".

• This is probably easy for a computer to parse, but as a human, if I saw that, I would have no clue what the duration represented (and I suspect the vast majority are not familiar with ISO8601). If an audience is familiar with the standard, it might be a good solution though. Mar 29, 2017 at 13:54

You have to be VERY careful when using time. For example,

1:54 could mean

• 01:54 AM - A time
• 13:54 PM - A time
• 1 hour 54 mins. - A duration
• 1 min. 54 seconds - A duration
• 1 out of 54 - a ratio
• probably many others

So your best bet is to know your target audience. For example office workers that always work 9am to 5pm will see 1:54 is 1 hour 54 mins. after 12 - noon. While an audio editing team of people may see it as 1 min, 54 seconds.

So, that leaves us with a few options if your trying to get everyone to understand.

1.90 hours is a good start. 1h54m is decent 01:54:00 is good too 01:54.00 is good I would choose, personally

114 mins.

or

two columns

``````Hours | Mins
1     | 54
``````

Both are easy on the computer and hard to misunderstand.

• I would read "01:54.00" as "1 minute, 54 seconds, and no hundredths of a second" Mar 29, 2017 at 17:54
• 1.90 hours is a bad start. I have never in my whole life seen anyone write a duration using decimal fractions of an hour. Mixing colons and periods is bad for exactly the reason @warren gives. Mar 29, 2017 at 18:44
• @DavidRicherby I see decimal parts of hours a lot Mar 29, 2017 at 19:14