January 20: *The Powerhouse bumpers receive a major overhaul. The "Powerhouse" remixes are inexplicably dropped, replaced with background music from the shows themselves. Also, prior to 2003, some shows had multiple patterns of bumpers, which were unified into one pattern afterward. In addition, the majority of the bumpers seen from 2003 to 2004 only had the blue and purple backgrounds, as the green, yellow, and dark blue bumpers were long gone by the beginning of 2003 (with the strange exceptions of the "Coming Up Next" bumpers until May 2003).
January 12: Adult Swim begins airing on weekdays, with the exception of Fridays. The Saturday action block is also dropped until April 17, 2004. In addition, the block receives its first rebrand, as the bumpers featuring old people swimming are replaced with bumpers featuring pages of a handbook. To celebrate the rebrand, reruns of soon-to-be cancelled FOX show, Futurama, are added to the block, a move which later results in the show’s revival on Comedy Central.