Do you plan on adding English day postfixes? I.e. st/nd/rd/th.
I’m not quite sure about the parsing being missing, even though I can appreciate the technical arguments. If the aim is to make Elixir seem like more “complete” to a user, as apparently some are surprise by the lack of formatting/parsing/TZ stuff in the core, then this will just move it to being surprised about parsing being missing. Many users will just have to go for some calendar library anyway if they want parsing. Add to this the TZ stuff being added into core, the UX will soon be that Elixir contains sort of half of a datetime library and for some reason the user will have to get a package to fill in the rest. This is just a first impression though, so don’t take it too strongly. 
