Statistically speaking:

As part of my research, I've collected data from more than 20,000 people who report how happy they feel at randomly selected moments during daily life. These data reveal that we actually are happier than usual on holidays. In fact, Christmas Day, though not celebrated by everyone, is the happiest day of the year by a significant margin. Thanksgiving and New Year's Eve are not too far behind. While it's easy to call to mind spoiled children fighting over toys or distant relations making awkward conversation, the holidays are, relatively speaking, quite happy.