Fix date formatting on due date (again)

Fixes #834 (again)

scp/js/scp.js

@@ -303,8 +303,11 @@ $(document).ready(function(){
         $(document).on('submit', 'form', function() {
             $('.dp', $(this)).each(function(i, e) {
                 var $e = $(e),
-                    d = $e.datepicker('getDate');
-                $e.val(d.toJSON().substring(0,10));
+                    d = $e.datepicker('getDate'),
+                    day = ('0'+d.getDate()).substr(-2),
+                    month = ('0'+(d.getMonth()+1)).substr(-2),
+                    year = d.getFullYear();
+                $e.val(year+'-'+month+'-'+day);
             });
         });
     });