The pinball machine is Bally's "Eight Ball", 1977
This episode originally followed Super Bowl XII, where the Dallas Cowboys beat the Denver Broncos 27-10.
The title refers to the day that the Super Bowl, the championship game for American football, is played and has turned into a de facto national holiday. The event is usually the most watched television show of the year.
This episode was taped shortly before Super Bowl XII. The banner at Archie's bar had the right teams for the game (Dallas Cowboys & Denver Broncos). Arguably it may been the first prime time entertainment show to take advantage of a Super Bowl audience since it aired immediately after the game, a practice that is common today.
Louis Guss (Sam) had played one of the two deliverymen who carried in Archie's brand new color TV (in which Archie tipped them 50 cents - which they had to split) on "The Locket" (1972).