I think that early March will be the tipping point for a lot of places. You don't pay less rent in February, for example, just because it's 28 days.
I think the mid-tier places ($17-22 dinner bills w/o liquor), especially the chains, are going to be hit hardest. The little dumpling place by my house that has four employees, 7 tables, and most items under $7, they may actually pick up a little bit of business.