I agree - default the page to todays' date and throw up an error if the
users blanks it or throws in a unrecognised format. That's also a lot
better from a usability point of view..
I am guessing that 99% of the use of this screen will have the same
date as the current date. My suggestion at the moment is to default
the textbox to the current date and leave it at that for the moment.