>>211728109
It is set on Beltane which is in May.
The ritualistic sexual festivals at the start of the film, the themes of
>phallic imagery, rebirth, and sacrifice
>girls running through the fire
All Beltane.
It's bastardized a little bit, but there are no other antiquity holidays in that region that align.
Beltane is the first harvest (official midpoint between spring eq/summer sol)