Both of the current issues of Woman's Weekly Fiction Special and Take A Break's Fiction Feast refer to Christmas on the cover, have excellent Christmas stories and cheery Christmas messages from the editors.Personally I find it confusing enough to submit stories months ahead of when they're set without publishers moving Christmas into January.
Talking of Christmas, if you're one of those people who're often stumped when asked what you'd like, can I suggest this rather excellent writing guide?

