It's just that the unit tests are built on the assumption that if you go forwards 24/48/72 hours, the time will be the same but N day(s) ahead. And that breaks

It's just that the unit tests are built on the assumption that if you go forwards 24/48/72 hours, the time will be the same but N day(s) ahead. And that breaks down when you shift time zones. >don't test behavior with different dates It basically tests with different dates every time it's run.