Bug#993508: RFS: howardhinnant-date/3.0.1-1 [ITP] -- date and time library based on the C++ <chrono> header

[Andrea Pappacoda <andrea@pappacoda.it>]

> Did you check git history for that information?

Yes, and it was a really long process, since I used GitHub's web 
interface (as I'm not a Git expert). I attributed the copyright based 
on who created the file and to others who did major contributions to 
that particular file (following some advice found on 
https://reuse.software). I'm not a lawyer though, and any correction is 
appreciated :)