The late 1970s saw the premier of two weekly television series based on Marvel Comics characters: The Incredible Hulk and The Amazing Spider-Man. Both aired on CBS and both began as made-for-TV movies. A ninety-minute telefilm called Spider-Man, starring Nicholas Hammond, was broadcast on Wednesday, September 14th, 1977 from 8-9:30PM. Several weeks later, on Friday, November 4th, The Incredible Hulk was aired from 8-10PM, starring Bill Bixby and Lou Ferrigno. A second made-for-TV movie, The Return Of The Incredible Hulk (also known as A Death in the Family), followed on Monday, November 28th from 8-10PM.
In the spring of 1978, weekly series based on both characters debuted. The Incredible Hulk premiered on Friday, March 10th, The Amazing Spider-Man on Wednesday, April 5th. The Incredible Hulk would stay on the air until November 1981, with another two episodes burned off in May 1982, while The Amazing Spider-Man wrapped its brief first “season” in May 1978; a second batch of episodes were broadcast sporadically between September 1978 and July 1979.
In the sixth issue of its Man from Atlantis comic book, published in July 1978 (meaning it was likely in stores sometime in April or perhaps late March), the “Bullpen Bulletins” page mentioned the premieres of both The Incredible Hulk and The Amazing Spider-Man. Here’s a scan:
Marvel Comics Bullpen Bulletins
Copyright © Marvel Comics Group, 1978 
Dr. Strange, the made-for-TV movie said to be airing in April, wasn’t broadcast until Wednesday, September 6th, 1978. It starred Peter Hooten and ran from 8-10PM. Nothing ever came of the Savage Sub-Mariner special, perhaps because of NBC’s Man from Atlantis series, which was not only similar to the character of Namor the Sub-Mariner but also a failure.
In 1979, CBS aired two made-for-TV movies based on Captain America, starring Reb Brown. The first, Captain America, aired on January 19th. The second, Captain America II: Death Too Soon, was aired in two parts on Friday, November 23rd from 8-9PM and Saturday, November 24th, also from 8-9PM.
1 From Man From Atlantis #6, July 1978, Page 30.