These are the late night schedules for the four United States broadcast networks that offer programming during this time period, from September 1989 to August 1990. 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.
| Network | 11:00 pm | 11:30 pm | 12:00 am | 12:30 am | 1:00 am | 1:30/1:35 am | 2:00 am | 2:30 am | 3:00 am | 3:30 am | 4:00 am | 4:30 am | 5:00 am | 5:30 am | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ABC | Fall | Local Programming | Nightline | Local Programming | |||||||||||
| Summer | Into the Night Starring Rick Dees | Local Programming | |||||||||||||
| CBS | Fall | Local Programming | The Pat Sajak Show | Local Programming | CBS News Nightwatch | ||||||||||
| Spring | Wiseguy | CBS Late Night | Local Programming | ||||||||||||
| NBC | Local Programming | The Tonight Show Starring Johnny Carson | Late Night with David Letterman | Later With Bob Costas (Mon-Thu, 1:35) Friday Night Videos (Fri, 1:30-2:30) | Local Programming | ||||||||||
The Pat Sajak Show was reduced to 60 minutes on October 30, 1989.
| Network | 11:00 pm | 11:30 pm | 12:00 am | 12:30 am | 1:00 am | 1:30 am | 2:00 am | 2:30 am | 3:00 am | 3:30 am | 4:00 am | 4:30 am | 5:00 am | 5:30 am | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NBC | Local Programming | Saturday Night Live | Local Programming | ||||||||||||
| FOX | Comic Strip Live | Local Programming | |||||||||||||
Returning series
New series
Returning series
Returning series
Returning series