If it is possible, I'd like to be able to select the hour and minute individually from the same popup/dropdown.   
Currently, if you set the interval to anything less than 15 mins the list becomes far too big, imo, and forcing the list to scroll isn't always the most usable way to do things, especially if that list is particularly large (intervals of 5 mins or lower).

It would be really handy if the user could somehow choose the hour and minute separately before the popup/dropdown closes. This would minimise space used because you wouldn't need every instance of each hour/minute combination. You'd just need the hours displayed, and the minutes displayed.

It would be nice to be able to add to the standard date time formats that the RadDatePicker allows.  I don't want to override the standard formats, just add custom formats (ex: ddhhmm MMM yy)

I have created a date user control using calendar extender. I have a textbox and calendar extender inside a DIV and its position set to relative and z-index is 1. When the page loads the datecontrol's popup is overlapped by the textbox of the second datecontrol. There is no problem with other controls. I have simple textboxes below that, but that is not overlapping. Please suggest a solution for me.

Support for Persian calendar.