June 15th 2015 and July 19th 2019 is 4 years 1 month and 4 days apart. That is the duration that occurred between the two dates and is totally unambiguous to non-programmers.
The fact that calendar distance and 'time' distance don't have a linear relationship and that math that governs the relationship between the different units isn't straightforward doesn't make it unprecise or misleading.
It's totally exact. Just because you can't convert the calendar distance to time distance without context doesn't make it any less exact. Not so different to being unable to compute distance traveled by the revolution count of your wheels.
If you are doing the financial calculation or similar, the month unit is absolutely inaccurate and you will keep asking about edge cases (otherwise you may lose money). And if you don't do that, you can cope with approximate units like months, half-months or so. There is no reason that the exact calculation of duration should be done in approximate units.
Once again, we're talking windows built-in calculator. I really hope the specification is "make it output something that the average user will understand and agree with". And the operative keyword here would be "average".
I'm saying that the Windows Calculator does disservice to the general public by showing the exact-ish year-month-day duration at all, it's like experts oversimplifying the complex situation and making laypersons more confused. Sorry if this was not clear.
June 15th 2015 and July 19th 2019 is 4 years 1 month and 4 days apart. That is the duration that occurred between the two dates and is totally unambiguous to non-programmers.
The fact that calendar distance and 'time' distance don't have a linear relationship and that math that governs the relationship between the different units isn't straightforward doesn't make it unprecise or misleading.
It's totally exact. Just because you can't convert the calendar distance to time distance without context doesn't make it any less exact. Not so different to being unable to compute distance traveled by the revolution count of your wheels.