[Plugin: Display Posts Shortcode] Call post with Certain Dates from custom field

Hi I would like to call all post that have a certain date here is what I”ve come up with but I get post but not the ones I’m looking for.
[display-posts post_type=”ad_listing” cp_sys_expire_date=”2012/06/21 00:00:00″ ]
`
Sorry My knowledge of php is slim, I know I’m doing the date, timestamp wrong, I don’t need a range just a specific day.

Thanks

http://wordpress.org/extend/plugins/display-posts-shortcode/