Agreed, this is true, for anything needs to independent from calenders. You find those problems typically on lower levels, in systems engineering (and I'm not s

Agreed, this is true, for anything needs to independent from calenders. You find those problems typically on lower levels, in systems engineering (and I'm not surprised you mention microcontrollers, I know many of those from there as well). The higher you go, the more likely you encounter a problem depending on timezoned timestamps and calendar calculation where it's not sufficient to just convert, say, UNIX timestamps to human readable format for presentation. Instead, time zones are inherent to the problem, and calculating on UNIX timestamps opens a world of pain for you and your users (simple example with microcontrollers: opening the doors at 9 AM). There is a wide application range for epoch based timestamps, but the tricky thing is to know when a calender based timestamp would be more applicable.