Sort on 'Modified' column is 'Show my files' page is lexicographic, rather than by date

Howdy,

The dates in the 'Modified' column look like

`Wed, 31 May 2017 19:57:53 GMT`

So when they are sorted in reverse order, entries prefixed with 'Wed' show up first, with 'Fri' entries being last. Vice versa for normal order.

My expectation is that they would sort according to

  YYYY-MM-DDTHH:MM:SS

instead.

Cheers!
Diab
