First there was bargain-friendly Black Friday, and now there's Blue Monday - the most miserable day of the year.
According to researchers who have analysed more than 2 million tweets over the past three years, the first Monday back from work in the New Year is the day when people post the most negative tweets.
There was almost five times the average number of tweets mentioning guilt, as people abandon their new year’s resolutions as they return to the daily grind.
Tweets complaining about the gloomy January weather were six times higher than usual, according to a drinks company who commissioned the research.
As if the mood wasn't low enough, the first day back to work will see solicitors start more divorce proceedings than any other day of the year. According to Divorce Depot.co.uk, 1.8 million couples will have argued at some point over the festive period.
Topics that couples disagree over most include finances, drinking too much, disagreements with the in-laws and chores.
Meanwhile, as people re-think their relationships in the New Year, extra-marital dating site IllicitEncounters.com sees a 25 per cent rise in activity after the festive break.
Those longing for happier days will have to wait until Valentine's Day, as researchers in a separate study say the happiest days of the year are Christmas Eve and Day, followed by New Year's Day, Valentine's Day, and the first sunny weekend of the year.