end date (public) post

Hello, please help.
My site is a list of cultural events.
There is a plugin that allows to determine the end of the post?
For example, U2 concert, which begins on 15.1.2009 at 20:00 and ends on 15.1.2009 at 22:30.
The Sidebar widget name – Today live
The widget in the Sidebar I have this php code:

<?php $current_day = date('d'); ?>
<?php $current_month = date('m'); ?>
<?php $my_query = new WP_Query("cat=67&showposts=1000&day=$current_day&monthnum=$current_month&orderby=date&order=ASC"); ?>
<?php if ($my_query->have_posts()) : ?>

so, U2 concert there 15.1.2008 appear and I wanted to 15.1.2008 at 22:30 disappeared.
Thank you for answers.