The NFL is coming off most-watched program in U.S. TV history with the Super Bowl, and its just-released 2014 schedule arrives today with a couple key differences from last year – one of which is bound to make NBC execs smile. The league said that its “flex” scheduling for the Paeaock’s Sunday Night Football games can begin as early as Week 5, moving up from Week 11 in the past. That means the NFL can move any scheduled day game into primetime to air on what has been the No. 1 show in primetime viewership for four consecutive years and tops in the adults 18-49 demo for six straight. But there is a catch: The flex option can be exercised only twice between Weeks 5 and 10, which means Fox or CBS won’t have to give up their best matchups every week during that span. The flex-scheduling say-so remains with the league, which must make the call no fewer than 12 days ahead of time. (Regular Sunday night flex scheduling remains in play after Week 10.) Meanwhile, the NFL also is introducing a plan to “cross flex” Sunday day games on CBS and Fox, which have over-the-air rights to the AFC and NFC, respectively. In previous years, a game between two AFC teams had to be on CBS, but now the league can choose to move those games to Fox (and vice versa). This could help during weeks when one network happens to have the potentially biggest games.