Consider re-adding Date and Duration #74
Description
We should consider re-adding the Date module from fp-ts v2 and adding the Duration module from @effect-ts/data. Possibly in the same file. The date type is a fundamental part of js and the Duration type makes it easier to work with differences between dates. Furthermore, @fp-ts/optic and @fp-ts/schema both support operations on dates so it makes sense to make this functionality part of the core lib as well.