there is a couple of changes that you will need to make, but we should be able to change the format.
First, look for this line of code:
changeMonth: true,
changeYear: true,
and change it to:
changeMonth: true,
changeYear: true,
dateFormat: 'dd/mm/yy',
the second thing is changing the spry validation. at the bottom of your page, look for a string 'mm/dd/yyyy' and change it to 'dd/mm/yyyy'
this should allow you to have UK date format.