wp_list_pages Format only on Recently Modified Pages

By default the function cannot do this, but you can specify a custom walker when you call the function, and then implement your own walker:

http://bugssite.org/blog/2009/12/08/wordpress-custom-walker-tutorial/

http://www.wprecipes.com/how-to-modify-lists-like-categories-and-blogroll-in-wordpress

This way you can keep the code the same, but add a check on the date of the page being walked over, and ‘skip’ it if it doesn’t match your requirements ( or add other desirable markup etc ).

more:

http://codex.wordpress.org/Function_Reference/Walker_Class

http://erikshosting.com/wordpress-tips-code/building-a-wordpress-walker-creating-custom-dynamic-menu-outputs/

http://www.maltpress.co.uk/2011/09/just-a-quicky-wordpress-custom-nav-walkers/

http://resources.mdbitz.com/2010/08/creating-a-wordpress-custom-page-walker/