Not exactly chrono crate (to quote "chrono or equivalent"). More like Java's version of chrono.

But what if we did that 5 years ago? Oops. And even Java's API has problems too. Why not let it be provide by the ecosystem where it can qctually evolve?

What problems does Java JSR 310 have (old Java time yes, but those are known issues)? As far as I have used it, it was damn near perfect.

It lacks a hybrid duration type. Instead, it splits durations into calendar and time durations and conflates the length of a `day` depending on whether it's in `Period` or `Duration`. And AFAIK, it doesn't support time zone aware duration rounding. And I don't see a way to compute a `Period` from two `ZonedDateTime` values in a way that respects time zone transitions.

To be clear, it's good. But there are mistakes that the Temporal project learned from and fixed.

(Temporal's single `Duration` type does have pros and cons, so I don't mean to frame having two distinct types as a strict negative. But it's very clunky.)