In an app that measures timespans, I want to express the overall value in a human-readable form.
Let's say we are measuring the time a machine runs, idles, is in standby or off.
The times are measured and easily combined. I want to give quick human-readable information like:
The Machine has been running for 10 months, 2 two weeks, 1 day, 3 hours ...
I know there is no correct way (ok, one could go with one-twelfth of 365.25 days) but that seems nonsensical.
Approximating a month to 30 days is one solution that seems understandable and 30 is a nice round number, and mathematically rounded from actually 30.4 days it would be somewhat correct.
Going with 28 days has the benefit that it covers even the shortest month and what I like most about this is, that is exactly 4 weeks. Also, the lunar month is usually considered to be 28 days.
Which way to count would be understood better by users?