> If nobody makes them, then how is that going to work?

I see it as “Dont write your own X, unless you want to maintain X. Here be dragons, this problem is deeper than it appears, the first 80% will be easy, the next 15% will annoy you, and the last 5% will consume your life for weeks, months, or even years. Or you could use a library”

The latter, if you want to get it completely right. I occasionally read the commits in the Qt framework, and from that, I can tell you that date-time stuff is complicated, and not in an instructive way, but in a super tedious way.