Hey Eugene I think it could just be that yyyy-Mmm-dd is not a normally used date format and isn’t recognized. I don’t think I have ever seen Apr 24th represented as “2017-Apr-24” so why do you want this format if it is one that really no one uses? Why not …
Apr 24, 2017
24.04.2017 (or for the ONE country who think they know better 04.24.2017)
24/04/2017 (or for the ONE country who think they know better 04/24/2017)
… pretty sure all the above formats are be supported as they are pretty standard.