Solved it by masking the control :
ASP:
<telerik:RadDatePicker ... DateInput-ClientEvents-OnKeyPress="KeyPress">
JavaScript:
<script type="text/javascript">
function KeyPress(sender, eventArgs) {
var keyPressed = eventArgs.get_keyCode();
if ((keyPressed > 64 && keyPressed < 91)
|| (keyPressed > 96 && keyPressed < 123)) {
eventArgs.set_cancel(true)
}
}
</script>
Quote:
Note that you can disable additional keyboard keys by using their ASCII code as showed in the example.(65-90 for capitalized letters and 97-122 for small letters).