I have compile and run the demo jQueryDatePicker with success.
I'd try to implement this but instead of the TIWEdit control is droped directly on the form, I droped it on a IWTabControl Page. But this don't work.
I think that the problem is on the line (.cal is the css of the control):

jQuery.OnReady.Text := '$(''.cal'').datepicker();';

This only works if the TIWEdit control has the form as owner. If it is inside a page of a IWTabControl, it doesn't work.

How can I solve this out?

Thanks