Move Date in WordPress

I want to move the date from the left column so text spans the full page with no empty space below the date all the way down the page.

http://obsessionfitness.com/

I'm able to shift the text left and increase the post width by adjusting the CSS for .postbody, but then the date is overlapping the header text.

How do I move the date to under the header, where the category and comments listings are? Thanks.

 

Add

&nbsp;|&nbsp;Published on: <?php the_time('F j, Y') ?>

Code (markup):

next to the

<?php the_category(', ') ?>

Code (markup):

in your index.php and single.php.