Heh… It can't represent UTC (leap seconds). Implementation weirdness like not being able to represent dates outside the 32-bit second counter range due to using a 32-bit second counter. The occasional need to store the TZ the timestamp is relevant in/to.

> It underpins basically everything in datetime database entries.

It does do that.

> The problem is that most people can't read that

This is why I prefer RFC 3339 or ISO, in that order.

> along with the French somehow never being able to convince the world to adopt decimal time.

Somehow. :)

maybe in space, but 2038 will have an interesting time warp.

Nobody has ever heard of "the French" undertaking such a project. And if it had ever happened, it would most surely have been a particular Academy or the like. Not the 65M people under your careless swipe.