How to denote time? Is it ok to use degree and prime symbols?


I'm aware that there is an international standard on how to display date-time, ISO 8601 ( But we all know that it's not that common. Maybe it is in engineering, but certainly not in design or everyday life.

I've seen quite a few ways to display time and one of those uses ' to denote minutes and '' to denote seconds. (Like in John Cage's 4′33″) I may be wrong but it seems obvious that this is "inspired" by notation for angles. Therefor I'm wondering wether it's ok to use ° (degree) symbol to denote hours. What do you think?

e.g. 1°35' (for one hour and thirty five minutes)

Additional information:
I plan to use it to denote short time spans, durations. e.g. "It will take about 2°15' to finish X."

2/8/2014 3:39:00 PM

Accepted Answer

The question asks about prime and double-prime symbols for minutes and seconds, which have been used for ages, and even feature in a piece of piano music (or what would be piano music, if there were a note played).

However it then veers off from the question title to ask about extending this to using degree ° for hours.


Prime/Double prime ′ and ″ can mean angular minutes and seconds or time minutes and seconds, or even feet and inches, but their variable meaning is context-dependent and easily grasped. The degree symbol universally means degrees: to force into a square-shaped hole for hours would be to make it unexpected and difficult to understand.

If you want a single-character for hours to complement ′ and ″, use h.

It will take about 2h15′ to finish X.

2/8/2014 4:38:00 PM

Though it is a pretty novel idea, I think your audience matters a lot. I would think very few people will get the variation on ′ and '' for denoting time. A few nerdy engineers and scientists might, and they will likely enjoy it and giggle in their beards.

Here is the problem: ′ which is not the same as ' are usually used to represent feet. To be more precise, it can represent feet, archminutes and minutes.

The '' which is not the same as " are usually used to denote inches. To be more precise, it can represent inches as well as archseconds and seconds.

(NOTE: these symbols might have different significance and meaning depending on country!)

3′ 5″ could mean 3 feet and 5 inches (of length), or 3 minutes and 5 seconds (of time). As an angular measurement, 3° 5′ 30″ means 3 degrees, 5 arcminutes and 30 arcseconds.

As for the degree symbol, though it is a nifty idea, again, I think few people will get it. "4degrees until this thing is finished"? Whhhaa?

You could pull it of, but this is heavily dependant on your audience, and you MUST have some visual clues along with it to get the "dimmer" people on board. Then, if you ask us what visual clues you could use in combination with your degree symbol, you might get some interesting answers. But I doubt it will be wildly user friendly.

Time is traditionally described with 02:34, or if you would be extremely clear: 00:02:34 to make sure people do not think that this will take two hours and thirty-four minutes.

Again, depending on your application, this is the normal way programmers do: 2minutes, 34seconds. And for being solid, it would detect anything below two and say "minute" and "second" for single values.