For the purposes of this post, I will define a prime time telecast as one with a listed start time between 7 and 9:30 pm ET (putting most of the game inside the standard prime time window of 8-11pm ET). This study focuses on games televised by national OTA TV networks.
Historically, the overwhelming majority of NBA games on national broadcast TV have been on weekend afternoons. While prime time telecasts have been common for the Finals, they have been anything but during the regular season. In researching NBA national TV listings on the forums at 506sports, I found only 20 NBA regular season OTA prime time telecasts and 9 of those were on Christmas night (including one doubleheader).
The first regular season NBA game televised nationally in prime time was a Lakers-Bucks matchup on ABC in 1970 featuring Wilt Chamberlain and Kareem Abdul-Jabbar. That telecast took place one week after the conclusion of the inaugural season of Monday Night Football. The most recent regular season prime time NBA telecast was on Christmas night in 2003 on ABC. The last such non-Christmas telecast came in December 2000 on NBC.
<UPDATE 1/22/2016 - Added a few missing telecasts from 1999 and 2000.>
Here is the complete list of regular season prime time national telecasts (all times ET):
Mon 12/21/70 - Lakers @ Bucks, 9 pm, ABC
Sat 11/26/88 - Lakers @ Pistons, 8:30 pm, CBS
Wed 12/25/91 - Celtics @ Bulls, 9 pm, NBC
Fri 12/25/92 - Knicks @ Bulls, 9 pm, NBC
Sat 12/25/93 - Magic @ Bulls, 8:30 pm, NBC
Wed 12/25/96 - Pistons @ Bulls, 8:30 pm, NBC
Sat 4/19/97 - Knicks @ Bulls, 8:30 pm, NBC
Sat 4/18/98 - Knicks @ Bulls, 8:30 pm, NBC
Sat 4/17/99 - Lakers @ Jazz, 8:30 pm, NBC
Sat 4/24/99 - Lakers @ Spurs, 8:30 pm, NBC
Sat 12/25/99 - Knicks @ Pacers, 7 pm, NBC
Sat 12/25/99 - Spurs @ Lakers, 9:30 pm, NBC
Sat 1/22/00 - two regional games, 8:30pm, NBC
Sat 4/8/00 - Spurs @ Lakers, 8:30pm, NBC
Sat 4/15/00 - two regional games, 8:30 pm, NBC
Tue 12/25/01 - 76ers @ Lakers, 8:30 pm, NBC
Sat 12/30/00 - four regional games, 7:30 pm, NBC
Tue 12/25/01 - 76ers @ Lakers, 8:30 pm, NBC
Wed 12/25/02 - Kings @ Lakers, 8:30 pm, ABC
Thu 12/25/03 - Rockets @ Lakers, 8:30 pm, ABC
Some other facts about NBA prime time TV games on national OTA networks:
- The first prime time network telecast was the 1968 NBA All-Star Game on ABC.
- The first network TV prime time NBA playoff game was a 1969 Knicks-Celtics matchup in the Eastern Conference finals.
- Game 7 of the 1970 Finals marks the first championship series prime time telecast. Prior to that, ABC had aired a few Finals games at 10 pm.
- From the 1971 playoffs on ABC through the 1976 playoffs on CBS, multiple games prior to the Finals aired in prime time each season.
- From 1976-77 through 1985-86, the only prime time telecasts on CBS took place in the Finals. During these seasons, CBS used the late night 11:30 pm ET slot with some frequency. For the entire 1979-80 and 1980-81 seasons, CBS did not air a single game in prime time. This was the era of tape delayed and late night Finals games.
- In 1987, CBS aired a pre-Finals playoff game in prime time for the first time since 1976. At least one pre-Finals playoff game has been in prime time on an OTA network every season since then.
- The All-Star Game received prime time OTA treatment in 1968, 1969, 1970, and 1973-1976. For the other two years in this range, the game started at 10 pm ET.