First science-fiction film ever produced in New Zealand.
The book "The Quiet Earth" is a time loop novel where the action begins and ends at 6:12. In the movie, Zac Hobson grows frustrated at the lack of a response to his radio message and throws a clock at the radio. When it breaks, it displays a time of 6:12.
The scene where Zac Hobson (Bruno Lawrence) is aimlessly wandering the empty streets of the city blowing on a saxophone was an in-joke to those who knew him, as he had once stolen one when he was young, but later felt guilty and returned it.
"The Quiet Earth" is actually based on the experience of an American tourist in New Zealand in the 1970s. New Zealanders always take the weekends off and sleep late. The tourist arrived in the center of Auckland on a Sunday morning and found it completely deserted. He later said he felt like the last man on Earth.
Interpretation of the final scene was addressed by the producer of the film on the DVD commentary. Sam Pillsbury states, "..It was quite simple; what happened was, he died at the moment of the effect for a second time and he's now found himself in another world, what the hell's he gonna do."