If you don't know what day it is then you obviously don't live in America. The Super Bowl is the most watched "show" attracting 111.5 million viewers last year. I don't even like football and I watch, but I watch for the commercials, which are getting pointless every year since I can just catch them on YouTube.
Since it's NBC's time to host this year, they have decided to put The Blacklist as the show to follow. Usually a network puts their top show or newest hit show as the follow up act after the game to get new viewers, but it doesn't always work. The last two didn't see any real gains afterwards (New Girl and Elementary), but maybe The Blacklist will change that streak.