Formatting “days” in a timespan

Question

When formatting timespans in short form for something like a stopwatch, I know the standard in most places is to use hh:mm:ss.ff (where "f" is "fractional second"). Some places will use mm' ss" ff, which is also okay.

What about days, though? I've never seen a consistent standard, or such a thing being used much (currently I use the longhand, ddd days hh:mm:ss, but I think that looks ugly because the days get disproportionate spacing). What ways are there of doing it? Also, when using mm' ss" ff, what do most people use for hours?

Answer 1

A lot depends on what you are trying to time, how accurate it needs to be, and who your audience is.

If you were timing an olympic event, you would at most need hours, but you may need thousandths of a second. But if you were timing how long it took to build a house, you would most likely need it to count into years at maximum and your maximum resolution may be days.

If you don't need accurate timing, I would follow this site, and only show the most significant information. So if it is really new it may be '7 minutes', but if it were a little older, it would be '2 hours' without showing the minutes. The progression in that case is usually: seconds, minutes, days, weeks, months, years.

If you need to show more accurate timing over a wide time scale, I like using an indicator for each unit. So something like: 34d 12h 17m 54.23s is very clear.