Halloween

Halloween was a human holiday traditionally celebrated on 31st October.

On Halloween 1938 Orson Welles broadcast a radio play adaptation of H. G. Wells' novel The War of the Worlds, convincing certain members of the American population that Mars had really invaded. (BFA: Invaders from Mars)

On Halloween 2009, the Hervoken tried to take over the New England town of Blackwood Falls. (NSA: Forever Autumn)

On the same day, Torchwood 3 had to deal with alien predators. (TWN: Pack Animals)