I GUESS YOU THINK EVERYONE WILL PLAY ON CHRISTMAS, WHEN THEY SHOULD BE WITH THEIR FAMILY AND FRIENDS IN CELEBRATION!! WHO WAS THE HEARTLESS PERSON? WHO THOUGHT IT WAS A GREAT IDEA??
Wars are every two weeks,Raids every 4 weeks, calendars seems to be around every two weeks,and if there is a holiday that is usually the theme,if you have plans then skip it,decide what is important, for you and enjoy it.
The schedule for events is set up way in advance on an automatic rotation. Sometimes they will line up with real-life holidays or other events and that's just the way of things.