 FACT: When Duane returns to Anarene toward the end of the film, he  is on leave from the US Army in the middle of the Korean War, around  1952. His hair is clearly too long to pass Army regulations, which  limit the length of a soldiers hair, after he has completed basic  training. His hair would be too long even for todays Army.  Moreover, Duane has sideburns, which the Army would never have  permitted.