The depiction of Earth in 2155 in the opening scene is a footage of Moonbase Alpha taken from Space: 1999 (1975).
The first scene is set on November 10, 2155. This episode was originally broadcast on November 10, 1978.
Ted Shackelford (Adam Clement) and Joan Van Ark (Cassandra Loren) would later star as Gary and Valene Ewing in Knots Landing (1979), roles which they originated in Dallas (1978) and reprised in Dallas (2012).
This episode takes place on November 10, 2155 and in 1978.
Adam refers to a nuclear apocalypse in 2007, but the actions in this episode may have changed that chronology. At one point, I.R.A.C. is about to disclose a secret to Adam, potentially its conclusion that Diana Prince is really Wonder Woman, but they're interrupted.