I dunno; when I go through it, it works.

First, you must initially select a date, otherwise it won't process the request for a special rate.

Then if the rate is available, it gives you the rate. Down below, you will see a box that says:
So you click on that. It will take you back to where you select a start date and time interval. Then you select the type of room (there may be rate differences depending on whether you want Queen, King, etc. Click on what you want and you get the calendar.