I guess people have forgotten about the year 2k problem, where nuclear power-plants where to explode, nuclear missiles was to fire, the world would end, because the year would be reset from 99 to 00. A lot of resources was put to fix it. And when the millennium finally changed, nothing really happened.

That said, I cringe every time I see a date problem presented in a work interview or challenge. Like how to calculate the first Monday in a set year. Because I have done exactly that, professionally. And as the years went by - edge case over edge case showed up, making me rewrite the formula. So dates are non-trivial. You probably know there are leap years, but did you also know there are leap seconds ? So beware of that when you implement that time critical database redundancy and replication system.