I noticed the the F6 key clears the DateBox control and I don't see a property to set that value. What is the best way to set the "delete" key to clear the value?

Well, this property should be slightly exposed, but delete would technically interfere with other logic in the control. The delete currently deletes any selected text in the control. Let me tinker with this a little to see if it is safe for us to expose this property. The other option is to subclass the DateBox and override the ProcessCmdKey which gives you the base entry point...but this is one of those "Do at your own risk" things.