If you look in the edit history on this page, you will see roughly what I had in mind on the Talk page for the Main page. [[User:Frjohnwhiteford|Frjohnwhiteford]] 10:23, April 19, 2007 (PDT)
: This syntax won't work for the main page, though, because the main page's feasts are based on an automatic variable that "knows" what day it is and includes the proper template accordingly. If you know how to make the wiki calculate -13 from the date it "knows," then we're in business.
—[[User:ASDamick|<font size="3.5" color="green" face="Adobe Garamond Pro, Garamond, Georgia, Times New Roman">Fr. Andrew</font>]] <sup>[[User_talk:ASDamick|<font color="red">talk</font>]]</sup> <small>[[Special:Contributions/ASDamick|<font color="black">contribs</font>]]</small> 13:45, April 19, 2007 (PDT)