I noticed recently my comic listing was no longer being checked for updates on The Webcomic List website.. When I inquired as to why, Norah was able to help me with this letting me know its because I needed to have <!– Last Update dd/mm/yyyy –> in the HTML code for the page listing the last date the comic was updated. Simple enough except that I use Drupal, the only HTML code on the site is generated via PHP scripts.
After a few days of testing, a little research on PHP script sites, and more help from Norah; I was able to piece together the right PHP code which updates the date code automatically every time I post a new comic, and the right placement of the code to get my site to work with the TWCL system.