WP Nav Menu

I have the exec php plug-in and am using this code below to display the menu links. It works well, but I want to have the date the link was created show up before the A tag.

<?php wp_nav_menu(array('menu' => '144', before => 'text here')); ?>

In the code above, the same text shows up (of course) before the links in my custom menu, but the WP help page says that something like get_date can be used, but I have no idea how to do it.

Can someone please help with a little code, please?