The CW is an American television network, which launched on September 18, 2006 as a programming and management consolidation of its two predecessors The WB (majority-owned by Time Warner) and UPN (owned at the time of that network's shutdown by CBS Corporation), both of which began broadcasting in January 1995. For broadcast affiliates, the station's advertised channel number follows the call letters. In most cases, this is the station's virtual channel (PSIP) number.