Employers are being urged to "cut employees some slack" as today marks one of the year's "unhappiest" days.
Today (3 January 2012) is the day reality bites as most will return to work after a (mostly) enjoyable Christmas break.
The gloomy weather ensures the UK's mood is just about at its lowest.
Further confounding the nation's misery, it is also believed today will see the highest number of divorce petitions.
January as a whole is said to be the year's "unhappiest" month with the highest number of suicides occurring at this time.
A study of nearly 14,000 people by Moodscope.com last year showed people's moods plummeted to their second lowest on this date - a day marginally pipped at the post by the year's absolute worst on March 20th.
"On the face of it, discovering that today is one of the year's gloomiest could be seen as yet more bad news, but we like to think that forewarned is forearmed," said Jon Cousins, founder of Moodscope.com.
"Knowing that people's moods are likely to be low on January 3rd suggests you should do what you can to look after your own wellbeing, and also – certainly – expect others to be a bit glum that day too. Cut them some slack."
People's moods were measured by Moodscope.com using a test asking respondents to rate themselves as to what extent they feel upset, ashamed, guilty, alert, enthusiastic, strong etc.
The individual ratings were used to produce an overall percentage score where 100% is extremely happy and 0% is abjectly depressed.