When to take down the Christmas tree

I am often asked as a designer how long after Christmas is it socially acceptable to keep the Christmas tree and the decorations up.  After all January is dull and bleak if you live in the northeast.  The glow of lights often helps with depression in the darker winter months. Here is my answer. If it makes you happy take decorations down slowly but by the 3rd week in January you need to be done. Please savor these last moments of the season.