When other biblical events were taken into account - Herod, the wise men led by a prominent star - it was concluded by some investigators that Jesus was born several years earlier than ZER0 BC/AD, more likely 4 BC, and that the event would have taken place in about October, which would make an early December conception a possibility - but then, what grounds are there for thinking that the Christian date for celebrating the conception is based on anything other than taking over a feast from an earlier religion?