Brain not in gear just yet.
Have a look at:
http://www.lebans.com/monthcalendar.htm which will get the calendar to update a text box, then IIRC in the textbox 'afterupdate' event, you need to run the query.
Use VBA code to pu the forms query code into the 'data source' and refresh, this should then have the form open and display the records you want.
Depending on the speed of your requirement, I recommend a sift at accessmonster, or a short delay until I can get my brain in gear.
ZH