The time to put your Christmas tree up depends on a few factors. Firstly, it is important to consider how long you want your tree to stay up. If you want it to be up for the entire holiday season, then it's best to put it up early in December. However, if you want it to be up for a shorter period of time, then you can wait until closer to Christmas. Additionally, it's a good idea to put your tree up before any major parties or gatherings, so that you can enjoy it without having to worry about decorating it at the last minute.