[hyperman1]

Clarification for the Dates thing: You implement a date as a datetime where time=00:00:00. BUT a timezone mismatch between application and DB means today 00:00:00 might change into yesterday 23:00:00 so everybody who claims you can 'just' ignore the time is subtly wrong.

I had a lot of fun troubleshooting an issue where a country was invaded in WW2 so it joined the German time, but its neighboring country was not. Hence, only in part of WW2 and only in summertime the time zones between these countries differ. Server was of course installed in the neighboring country and then delivered without altering the time zone because who cares about something that subtle. Turns out everybody born in these specific half years had their birthday shifted by one day.