When Does "Indiana Jones and the Raiders of the Lost Ark" (1981) Take Place?
"Raiders of the Lost Ark" (later released as "Indiana Jones and the Raiders of the Lost Ark") is a crime? historical fiction film written by George Lucas with Philip Kaufman and Lawrence Kasdan that released June 12th, 1981. So when is "Raiders of the Lost Ark" set?
It takes place in the year:
We know this because Adolf Hitler's Nazi regime appears, as is clear from swastika armbands on soldiers, which only existed from February 24th, 1920 AD until May 8th, 1945 AD (the swastika was adopted as their logo sometime in 1920 AD).

1936 AD
We know this because Adolf Hitler's Nazi regime appears, as is clear from swastika armbands on soldiers, which only existed from February 24th, 1920 AD until May 8th, 1945 AD (the swastika was adopted as their logo sometime in 1920 AD).
Furthermore, very early on there is a white time and place setting title card superimposed over the footage reading "SOUTH AMERICA 1936".
It was adapted to prose in early 1981, as a video game in late 1982, then in 1994, in 2008 and in 2009.

