Christmas cards and letters

This week in the United States, many people will be celebrating the Thanksgiving holiday. Here, many people who celebrate Christmas wait until after Thanksgiving to start decorating for Christmas or sending out Christmas cards and letters. (Although, I have already seen Christmas decorations on several houses in the area, and the stores have had Christmas stuff for sale since Halloween or earlier.)

I'm curious about Christmas greetings in other countries. Here, we have the day after Thanksgiving as the unofficial start of the Christmas season, and I'm wondering when people in other countries start preparing for Christmas. Do you start earlier than us, beginning with Halloween, instead of Thanksgiving. Or, do you start later than us, waiting until Dec. 1 or later to start sending out the Christmas cards and letters?

I'd love to see some comments on this topic!