Earlier quoted context omitted.
Indeed. Raven are not very much religious and don't tend to celebrate religious holidays.
Serious question (I don't know that I know any atheists): do atheists not eat ham and turkey, and give their kids presents on Christmas? I would have thought this was more cultural than religious in the USA.
Winter solstice is December 21. It makes sense to have gatherings around equinoxes and solstices since they are turning points in the year.
That being said, most atheists come from religious regions or families. They consider those holidays their heritage and celebrate them. Christmas is seen equally to, let's say, Halloween. Nobody cares about Samhain but they care about candies. Nobody cares about the birthday of Jesus but they care about receiving their family and giving them gifts.