It is uncontroversially acknowledged by any Christian scholar or historian that Christmas takes place on December 25th, in an attempt by the Church to "cover over" or co-opt a pagan holiday.
The cult of Mithras was more popular in its day day than the fledgling Christ Cult. However, it was a male-only cult and by the time of Emperor Constantine and his son Theodophicus, it was all co-opted into the larger Christian Institution.
Mithras killed the bull and was born on December 25th. He is said to have died and resurrected in three days.
Neo-pagans hope to revive the religious traditions that were erased, co-opted, and covered over during the 4th Century.
However, this movement is not JUST a reactionary or romantic movement.