The most i've ever hurt my brain was reasoning about a timezone-aware fleet management system, and what it meant when a vehicle was driven from one timezone to

The most i've ever hurt my brain was reasoning about a timezone-aware fleet management system, and what it meant when a vehicle was driven from one timezone to the next while properly billing the time driven. We ended up going with an 80% solution that we know is wrong in some cases, but that we an actually explain to users.