There's an issue in the datepicker on the client side and this fixes the issue.
Issue was that the date was not correctly translated, so when for example we had configured `yyy-MM-dd` and when a user selected a date using the datepicker on the open.php (custom form with date/time field) it showed `201717-January-1818` instead of `2017-01-18`. This PR fixes this issue and I guess it was forgotten by Jared once he made the format i18n aware in commit https://github.com/osTicket/osTicket/commit/0fbc09ad512552b9c356c983121797b0e6c2c22f, in which he changed it on the backend side, but not on the user / frontend side. Tested it with 1.10.

Cheers,
Michael