Time period??? Hmm, maybe about 1974. The film: A tragedy and anti hero combined into one. A person with massive post traumatic stress, (Not military related). Living in the lower class of "Gotham". Reminding me of Blade Runner, one of the have not's on the street level. Also, something like the movie Falling Down. Scene after scene nothing can go right with the Joker, his life keeps sinking into a deep mess. Later in the movie he seems to gain confidence within himself and sort of fights back at society. To myself he reminds me of the circus elephants which attack their handlers. They just snapped due to the harsh treatment, to the onlooker the elephants are crazy and unpredictable monsters. To the other elephants who are present and an understanding individual who can comprehend the situation, the elephants are simply sick of their treatment and have had enough. Just like the Joker.