Creating a form that displays results for a certain date?

What is the process for creating a form that will return all records for a certain date?  Or rather, how can I incorporate a variable into my SQL syntax?

Preferably when a user opens this form, they would select a date and a subform would render the records that match that date.  Something along the lines of SELECT * FROM visits WHERE visits.date=variableDateFromForm

Thanks in advance!