> Use proper date/time datatypes, and manipulate them with library functions. The point is: What do they do? There are plenty that will use... Unix timestamps

> Use proper date/time datatypes, and manipulate them with library functions. The point is: What do they do? There are plenty that will use... Unix timestamps (or worse). Or use those as the lowest common denominator for interchange. There are more systems at play than the data layer, and all of them will take every opportunity to bite you in the arse.