In professional American football, the Super Bowl is the championship game of the National Football League (NFL) in the United States. The game and its ancillary festivities constitute Super Bowl Sunday which over the years has become a de facto U.S. national holiday.
The first game was played on January 15, 1967 as the AFL-NFL World Championship Game in which the NFL championship team played against the champion of the younger, rival American Football League (AFL) for the "World Championship of Professional Football". After both leagues merged in 1970, the Super Bowl became the NFL's championship game. Since then, the game has been played annually on a Sunday following the playoffs, originally early to mid-January, then late January, and in 2002, the first Sunday in February.
The Super Bowl is one of the most-watched U.S. television broadcasts of the year, attracting many companies to spend millions of dollars on commercials. This has caused the starting time of the game to be pushed back later and later, to ensure the Sunday night prime time audience on the East Coast. The last true day game (which ended before local sunset) of the series was Super Bowl XI in January 1977.
In addition, many popular singers and musicians have performed during the Super Bowl's pre-game and halftime ceremonies. This is the second-largest U.S. food consumption day, following Thanksgiving.
The Super Bowl uses Roman numerals to identify each game, rather than the year it was held. The NFL season spreads over two calendar years, so identifying the games by the year of the Super Bowl could cause some confusion. For example, the Tampa Bay Buccaneers, winners of Super Bowl XXXVII are the champions of the 2002 NFL season, even though the championship game was played in January 2003.