Well, this is sort of strange. A report is a passive entity. It gives back to you information that you collected in a table. The information you got in the table was generated by a query or entered. The way the user gets to all of that is via a form.
You don't enter data into a report. A report is one way: out (to the screen or printer). Therefore, the place to ask for the date and execute the query is at the form. Enter the date at the form, then the form runs the query which accesses the table. When it's done, the form then opens the report with the correct recordsource.
Entering the date in a form should be very easy. Then the user can either click or button you can put an AfterUpdate event on the date field.
Michigan Dept. of Environmental Quality, Air Quality Division