To do that you first need to choose a calendar and a time zone, then convert to that representation. It can be done, but you need a good implementation that understands the entire history of what has transpired w.r.t. to date conventions in that location and culture. For timestamps in the future it is impossible to do correctly, since you can’t know how date conventions will change in the future.
However, I should add that as far as mathematical operations go, calculating the number of months between t1 and t2 is an entirely different thing than the duration of time that passed between those timestamps. Even if it is expressed similarly in the English language, semantically it’s something else. It’s like asking “how many kilometers did your car go” vs “how many houses did the car pass on the way”.
I feel like this is a solved and simple problem as long as there are no relativistic effects. Just make sure t1 and t2 are represented as seconds since a known reference time, e.g. Unix epoch, and make sure that measure is accurate. You don’t need to bring the Gregorian calendar into it, use TAI represented as an integer.
The sites won’t say “we rip off our artists and they’re very unhappy about it”. In fact as far as I can tell from visiting spotify.com, Spotify is just fine. So this is apparently not a sufficient method for finding out if a site is a good way of buying music.
I checked a couple of songs on my playlist and didn’t find places that were obviously better than Spotify. Is Bandcamp better? How about Beatport? Being able to buy and download music is not a guarantee that the artist is getting paid fairly.
As a side note I’m growing weary of having to keep track as a consumer of the revenue streams and ethics of every brand out there. There’s a lot on my plate already. I wish that if musicians didn’t want me to buy things for a certain price or at a certain place, that they just wouldn’t offer it to me in that way. Or, if they were being coerced into it, that they would push for regulation to prevent that. But I have a suspicion that the principle of supply and demand dictates that selling music online just won’t be as profitable as they (naively) expect it to be. Too many musicians, too few ears.
Why are you not moving to a different distribution model where you’ll get what you’re worth? I’ll go where the music is. If you keep putting it on Spotify then I’ll play it on Spotify.
If they don’t have a regular bus system that works then that’s what they need to start working on first. I’m convinced that it can be made to work if they are solution oriented instead of only looking for reasons why it won’t work and stopping there.
Where I live, buses have dynamic routes. You go on an app to book a journey, then you get a time and place to be where the bus will pick you up (plus a drop-off point). It works for school kids as well as anyone else.
That was my initial thought too. But if Vader can stay at a distance and force-choke Wolverine until he’s passed out, then Vader could move in after it’s safe and basically burn up every ounce of Wolverine’s body except for the adamantium using the light saber.