Naming.
Timestamps.
No, the original joke, which GP is referring to, is “There are only two hard things in computer science. Naming things and cache invalidation.”
It predates 1999 and the Y2K bug by a fair amount. I first saw it on Usenet in the early 90s, around 1994 I think.
More like
There are only two hard things in
computer science. Naming, cache
invalidation, and off-by-one bugs.It only started causing widespread issues with the rise of cross-region internet SaaS. Database systems, language runtimes, and OS APIs are keeping the default behavior for backwards compatibility.
So in practice, while it was kinda useful to be locale/region dependant for some users it's probably been more trouble in the long run to be overly helpful.
C# was released after y2k, so they don't have the excuse.
Also, You're missing the biggest sin here however, locale specific time is OK, automatically allowing conversions/comparisons to points in time types without specifying timezones has in principle never caused anything but grief.