It doesn't surprise me. Timezones - and dates and time in general - are extremely complicated. Deceptively so. Although we interact with timezones, dates, and time every day, we don't think about layers of complexity and edge cases. More importantly, we don't practice them.

We have courses about compilers, databases, data structures, algorithms, cryptography. It's surprising we don't have courses about dates and time.

Yes .NET's DateTimeOffset was my baptism. See https://stackoverflow.com/questions/4331189/datetime-vs-date.... So confusing. Definitely readying that SO post again if I need to use it.