@drewdevault TIL date::reckon
makes me wish more languages would have something like this.
@lanodan
The name was my idea, to "reckon through a chronology" as opposed to just a univariable timescale (date::add()). You "reckon" since sometimes you don't know where you'll land if at all, due to a timezone discrepancy or field overflow (something we're still working on).
In my research, most stdlibs unify it all into one "Add()" function, a verb which doesn't sufficiently hint at what is essentially a complex vector operation (<Y,M,D...> + <Y,M,D...>). Time will tell (heh) if we made a good design choice.
Also, nods to @vladh for helping with the implementation.