Time shut off for joomla 1.5 article

I need a small Joomla 1.5 plugin that I can add to an article so I can set the time to redirect to another page. We have multiple events page that link to registration form for each event and after a set time we want the link to redirect to a page that says "sorry todays event is now closed". This is to be set at 8pm for every event We want a Joomla 1.5 plugin so we can simply add the plugin along with the redirected URL and the time set to close the registration and undertake the redirect and add the tag to any article as required.