It is the celebration of the Nativity: nothing to do with mid-winter.
Bash is correct.
Solstice is the 21st month. The winter Solstice the 21st December.
What I find interesting is that the experts as you call them Shakes, all say the pagans stole the dates and even shifted to make themselves look as if they always used that time.
Truth is everyone wants to connect their beliefs to the Christ.
Or even make out their beliefs older. But as God created everything then God gets to be the oldest belief.
I wonder if people get really jealous of how Christ has stuck around for all these centuries and is wider known and understood more than any other belief.
I guess their is room for all beliefs. But trying to steal a celebration is a little childish. Christmas Day is for Christ. You can't change it can you.