Hi again,
i have solve my problem. I have write a JavaScript function like this:
function HandleUpdateDateEdit(s, e) {
var DreissigJahre = new Date(s.selection.firstSelectedInterval.start);
clientDateEditor.GetDate().setDate(DreissigJahre.getDate());
clientDateEditor.UpdateDateEditInputs();
}
And i call it on the ASpxScheduler ClientSideEvent EndCallback like this:
<ClientSideEvents EndCallback="function(s, e){ HandleUpdateDateEdit(s, e);}" />