Now, following standards is great and all, but in my opinion, I think that the ISO and time like "2014-02-15T01:12:23" takes things a *bit* too far.
I would think it would be REALLY nice if you would take advantage of this provision of [https://tools.ietf.org/html/rfc3339 RFC 3339]:
NOTE: ISO 8601 defines date and time separated by "T". Applications using this syntax may choose, for the sake of readability, to specify a full-date and full-time separated by (say) a space character.
I don't particularly care if this is implemented as a new "RFC 3339" or "ISO-style" value for the option, or it replaces the existing "ISO 8601" value. But seriously, I'm not sure I've ever seen the T format in user-facing output *anywhere* else, and it's REALLY a pain -- not only is it hard on the visual centre of my brain, but also not very amenable to easy selection for copy+paste. (Firefox wants to select either none of the "15T01", or the whole chunk.)
Judging by http://www.cl.cam.ac.uk/~mgk25/iso-time.html, I'm guessing that the "T" was mostly meant to help in formats where fields are separated from one another by whitespace, and it is desired to have a combined date+time field.