An interesting book here is The Christ Conspiracy, by Acharya S. She argues that around the ancient world, (which is largely northern hemisphere coincidently), there are saviours and sons of Gods who are "born" on December 25th and have many life history features in common.
They not only include Jesus and Horus, but Ishtar, Mithra, Baal, Buddha, Krishna, Thor, Zeus and Odin.
The list also includes Osiris and Serapis unsurprisingly, given their syncretic relationship with Horus.
In essence they tell the story of the sun sinking to its lowest point at mid-winter solstice (December 21st/22nd) which represents the 'dying' of the sun, and then being resurrected/reborn 3 days later on the 25th.
She details the commonalities between a dozen or so from the list of over 50 and the similarities - birth to a virgin, dying for mankind, performing miracles, being resurrected and so on - are impressive.
Her thesis goes further to argue that essentially religions of the world are cosmological in nature, based on the sun, moon, stars and constellations, but then these are given human forms - which I believe is called anthromorphosis.
I don't recommend it to anyone who does not want their faith to be challenged, because it does make one think. But hopefully some of this is useful to your query.
Remember the famous words:
Logic is an ordered way of going wrong without realising it. Gnosis is the only way towards truth.