I mean, someone has to care.
Sure, but why can't that someone be a third party glue crate? I'd like to be able to have a chrono_diesel crate exist completely independently in the ecosystem.
Like always, I think modifying the coherence rules to enable more blanket impls is the solution here. We should have a base library (std presumably) defining the trait DateTime
I think the problem quickly becomes more general than what the standard library should be expected to cover. Take UUID as another example.