Actually, it was a 10 am start time. The thing at the time was that there were believed to be thousands of football fans in the Triangle who were frustrated by the conflict in start times. On that Saturday Duke started at 10 am, UNC at 1:30 pm and NC State at 7:30 pm (at the time, they were the only school with lights). The idea was that all those fans could take in a football tripleheader.
Of course, it didn't work that way. Just 12,000 fans showed up or the morning game in Wade... and attendance at Kenan and in Carter-Finley was normal. We learned that there were very few "football" fans in the Triangle ... just Duke fans, UNC fans and State fans.
Atldukoe, you are right that the Duke-Maryland series was sporadic in he '50s-60's and even 70s. In the first three years of the ACC, Duke and Maryland were unbeaten in the league -- but shared two titles because they didn't play each other (Maryland did tie a game in '55 that gave Duke the outright title). in 1965, it ended up costing us a share of the ACC title. Duke finished 4-2 but didn't play Maryland. State and Clemson played everybody and were 4-3. But later, the ACC forced South Carolina to forfeit all its games. That didn't help Duke, which had beat SC, but both State and Clemson had lost to the 'Cocks and their record was changed to 5-2 ... and the officially shared the ACC title.
But not playing Maryland almost gave Duke a share of the 1975 ACC title. The Terps finished the regular season unbeaten in the ACC. But they didn't play Duke. The Devils lost five non-conference games, but was 3-0 in the ACC when they got screwed out of a win vs NC State (the ACC later issued a formal apology for the blown call that cost Duke the game). The next week, a dispirited Duke team went through the motions against a terrible (3-7-1) UNC and tied them. Duke finished 3-0-2 ... unbeaten in the ACC, but second to 5-0 Maryland.