Answer:
It was an addition to the "Cigarette Labeling Law"
In a final concession to the broadcasters, the conferees agreed to delay for one day the blackout of cigarette commercials from December 31, 1970, to midnight January 1, 1971. That would give them a last shower of cash from the New Year's Day football bowl games.
President Nixon sight the Act into law on April 1st, 1970