I'm not a religious person but if you live in Mexico, as I did for four years in the 1980's/1990's, you can't escape the Virgin of Guadalupe.
Also known as Our Lady of Guadalupe, she is a representation of the Virgin Mary.
She is enshrined in a Mexico City basilica and Wikipedia tells me it is the most visited Roman Catholic pilgrimage site in the world.
The story of her discovery by an Indian peasant in 1531 is too long to relate here but you can find it at this site, if you're so inclined.
Today, December 12th, is her official feast day.
Once when I was living in Mexico I noted that December 12th was also the wedding anniversary of some friends of ours and not only that, it was Frank Sinatra's birthday!
It's also the first day SWMBO puts up a small display of Christmas ornaments.
So it's a good day to celebrate whatever you believe in.