The start of 24/7 broadcasting after CNN launched in 1980: This time, it was on local network affiliates. Meaning NBC affiliates carried Overnight, CBS News aired Nightwatch (now CBS Overnight News) and they even had the option to include CNN Headline News in their overnight lineup (ABC affiliates included after Nightline).
Early Risers Delight: this was for people who don't have the luxury of watching the CBS Morning News, ABC's Good Morning America or NBC's Today Show. They need to be right out the door to beat the morning rush. CBS Early Morning News, ABC's World News This Morning and NBC Early Today + local morning news = what early risers needed before getting to work or school on time.
ABC Late Night was never the same since NIGHTLINE Entered the Picture: Pre-1980 Consisted of wide world of entertainment, reruns of ABC primetime shows and movie of the week. Nightline with Ted Koppel launched in March 1980, giving ABC affiliates a post-late news alternative to Johnny Carson, who was a really big deal at rival NBC at that time.
And who knew that Jeff Greenfield would join ABC News later on, and the same person he interviewed (Roone Arledge) would be his boss?