NFL Saturday games are generally referred to by the league as its "exclusive game series" or branded with specific titles depending on the week, such as the "Saturday Showdown" or "Holiday Classic" (for Christmas Eve/Day games). The NFL primarily plays games on Saturdays late in the regular season (usually starting in Weeks 15, 16, and 18) after the college football regular season has concluded, in accordance with the Sports Broadcasting Act of 1961.