Well, it depends I guess on when they start. Advertising in December is not a good idea because nobody watches TV in December. So if they want to get viewers they should probably start airing them this month.
Also in Community's ball court, ratings are abnormally high in the first week of January for some reason. Last season, Whitney and Chicago Fire hit season highs and I think most of CBS surged that week as well.
Plus a hour long premiere should really help.