Is there a most depressing day of the year?

It's kind of a downer to think that there might be a "most depressing" day of the year, but then on the up side if today is it then it's already almost over. Back in 2005 a psychologist named Cliff Arnall announced that he had figured out how to calculate which day of the year was the most depressing, and in 2005 it was Monday, January 24th. Using the same formula would make this year's winner (if you can win at being depressing) today -- Monday, January 22nd.

Apparently there has been a lot of controversy over Arnall's formula -- with some saying it's just a marketing gimmick and others saying it's based on some very sound principles. Personally, I think some of the concepts do sound realistic, like weather and light levels as well as the general "let-down" feeling from the holiday season this time of year. But I think it's probably more realistic to predict a "most depressing month" or "most depressing season" as opposed to a specific day, and even then it would need to be calculated for individual people separately. There are just too many variables to try to pin something so personal as "mood" down to one day of the year.