Storing a Post's Date in A Variable, Then Using That Variable in query_posts

I did a long-winded explanation here(http://ww.wp.xz.cn/support/topic/creating-an-issue-date-algorithm-that-can-work-in-outside-the-loop?replies=1), but, basically, how can I get a date one post was published stored in a variable, and then use that variable in future loops?

I’ve made a few attempts using the_date() and post_date, add_filter, and other means, but can’t seem to get the format of the date in the variable to work with the query_posts.

Here’s one very simple approach I’ve taken to get the date stored in the variable:

`<?php query_posts(‘orderby=date&cat=135&showposts=1’); ?>
<?php while (have_posts()) : the_post();
$issuedate = the_date(‘F j Y’);
endwhile;
?>`

But I can’t seem to get that date information to work with query_posts to return only posts with the same publishing date.