First, I assume you store event date in custom field properly. Native WP post published dates are really not meant for future events, since future dates are used for scheduling functionality and make posts non–public.
From there it’s just a matter of putting together appropriate get_posts()/WP_Query to retrieve your set.
Modern WP version allow very elaborate meta queries, including support for MySQL’s DATE and DATETIME formats (though I highly recommend to store time as unix timestamps internally).