Nickelodeon on CBS

Nick on CBS (also known as Nick Jr. on CBS) is an  American Saturday morning children's programming block that ran on CBS from September 16, 2000 to September 9, 2006. The block featured programming from Nickelodeon, which was a sister cable television property to CBS under Viacom for the majority of the block's run.

History
In June 2000, a few months after Viacom (which CBS founded in 1952 as television syndication distributor CBS Films, Inc., and later spun off in 1971 after the then-recently implemented Financial Interest and Syndication Rules barred networks from holding financial interest in syndicated programming content) completed its $37 billion merger with CBS Corporation, CBS reached an agreement with new corporate sister Nickelodeon to air programming from its Nick Jr. block beginning that September.

The new four-hour block, Nick Jr. on CBS, debuted on September 16, 2000, replacing the Nelvana-produced animation block CBS Kidshow, which ended its run the week prior on September 9. For the first two years of the Nickelodeon agreement, the block exclusively aired preschool-targeted programming from Nick Jr., including interstitials from the Nickelodeon block's animated mascot, Face. In June 2001, the block was reduced by one hour, reducing its length to three hours, and removing Maggie and the Ferocious Beast and Maisy to allow for The Saturday Early Show. In September 2001, the block had a rebrand, adding shows like Oswald On September 14, 2002, the block was rebranded from Nick Jr. on CBS to simply Nick on CBS; at that time, its programming content expanded to animated Nickelodeon series aimed at children between 7 and 16 years of age, in addition to two Nick Jr. series.

As with the predecessor CBS Kidshow and Think CBS Kids blocks, all of the programs within the block complied with educational programming (E/I) requirements defined by the Children's Television Act, although the educational content in some of the programs was tenuous in nature. It was partly for this reason why some of Nickelodeon's most popular programs (most notably, SpongeBob SquarePants – at the time the cable channel's most popular series) were not included as part of the CBS block, even during the more open-formatted Nick on CBS era. However, some airings of SpongeBob SquarePants, The Fairly OddParents, Doug, Rocko's Modern Life, CatDog, The Adventures of Jimmy Neutron: Boy Genius, and Rocket Power appeared during special holiday events on the block. Rugrats also aired briefly in 2003, when it was added as a regular series within the block. Somewhere in early 2004, the network had a relaunch, making additions like live-action shows, such as The Brothers García.

The older-skewing Nickelodeon series were removed from the block and Nick on CBS was rebranded back to Nick Jr. on CBS in September 2004, refocusing the block back exclusively toward preschooler-oriented series; the block also began incorporating interstitial hosted segments featuring Piper O'Possum. On December 31, 2005, Viacom formally split under the shared control of National Amusements (owned by Sumner Redstone), with CBS and all related broadcasting, television production and distribution properties as well as some non-production entities becoming part of the standalone company CBS Corporation, while Nickelodeon and its parent subsidiary MTV Networks became part of a new company under the Viacom name.

Less than a month later on January 19, 2006, CBS announced that it would enter into a three-year programming partnership with DIC Entertainment to produce a new children's program block for the three-hour Saturday morning time slot featuring new and recent series from its program library, to begin airing in Fall 2006. On September 9, 2006, Nick Jr. on CBS ended its run, and was replaced with a new block the following weekend called KOL Secret Slumber Party.