Proposal for custom time string formatting in std.datetime

[Kagamin]

>> If the compiler and/or linker don't strip unused symbols, then 
>> how on earth is
>> importing the module _not_ going to pull in everything in it 
>> save for
>> uninitialized templates?
>
> There are data that needs to be there, but is never 
> symbolically referenced, for example, the exception handler 
> tables. The compiler does the best it can, like emitting one 
> object file per function, but it always must behave 
> conservatively.

AFAIK, dmd used to remove unused modules but then bearophile 
complained that unittests are not run for imported but otherwise 
unused modules, so it looks like frontend's responsibility, not 
backend's.