If you have used the Lists module to program more than one list to appear on a specific date or time, the List Manager allows you to specify which list will override the other in the event of a conflict. For example, if a list called 'CHRISTMAS MENU' has been programmed to appear from 1 December 2007 to 24 December 2007 and another menu entitled 'Sunday Menu' programmed to appear every Sunday throughout the year, then you would use the List Manager to choose which overrides the other. In this case, the chances are the CHRISTMAS MENU will be the one you wish to have top priority in this example.
Simply drag the lists into order, with the highest priority items at the top.