Similarities between Samhain and Diwali?

Could the (superficial?) similarity be to do with the really ancient roots of Hinduism. No expert, just a thought. There again, Hanukkah is a 'light festival' (OK, candles only, no bonfires) at around the same time of year and that's commemorating a particular event - no connection whatever to either Samhain or Diwali.