The film is set on Sunday 30th October 1938, airdate of "The Mercury Theatre on the Air"'s famous Halloween broadcast of H.G. Wells' 'War of the Worlds' on CBS from New York.
As he prepares to abandon his family at the start of the movie, Hank Muldoon complains that he's 28 but looks like he's 40. Vic Morrow, the actor playing Muldoon, was 44 when the movie was filmed.
Actually CBS made numerous 'disclaimers' during the broadcast, which is why no one ever successfully sued to network or Welles, despite numerous lawsuits.
The announcer introducing the Mercury Theatre on the Air's production of "The War of the Worlds" names Orson Welles and Howard Koch as the writer. While Koch did write the script, he was not named in the introduction to the original broadcast.