If we make an input readonly it doesn't get validated and wee need it to be validated on a readonly datepicker.
In kend.all.min.js we have
v=":input:not(:button,[type=submit],[type=reset],[disabled])"
and if i modify it by adding readonly like below
v=":input:not(:button,[type=submit],[type=reset],[disabled],[readonly])"
We need to make that code configurable because the workarounds concerining this problem it's buggy.