These are the late night schedules for the four United States broadcast networks that offer programming during this time period, from September 1990 to August 1991. All times are Eastern or Pacific. Affiliates will fill non-network schedule with local, syndicated, or paid programming. Affiliates also have the option to preempt or delay network programming at their discretion. Legend Schedule Monday-Friday Saturday Sunday By network ABC Returning series Into the Night Starring Rick Dees Nightline New series In Concert '91 CBS Returning series CBS Late Night CBS News Nightwatch New series America Tonight Not returning from 1989-90: The Pat Sajak Show NBC Returning series Friday Night Videos The George Michael Sports Machine Late Night with David Letterman Later With Bob Costas Saturday Night Live The Tonight Show Starring Johnny Carson Fox Returning series Comic Strip Late Night United States late night network television schedules 1990 in American television 1991 in American television