This JEvents plugin allows you to restrict which events are visible in the frontend of your site.  For example you can hide all past event, or all future events or event just show events from 1 week ago to 1 week in the future.  Alternatively it allows you to constrain the dates for a specific menu item or module.

The plugin allows you to add a beforedate and afterdate filter to your JEvents Filter Module to allow site visitors to search for events in a range of dates