If you've switched on the news, read a newspaper or been on Twitter this morning, you will be well aware today is 'Blue Monday' - "officially" (we are told) the most depressing day of the year.
The UK media has bought into this in a big way over the years, coming as it does at a time when real news is often thin on the ground.
The story goes like this: Christmas is behind us and our bank accounts are empty. All that shopping in December cleaned us out and our January pay is still at least a week away. Many of us have broken our New Year's resolutions already and credit card bills and sky-high heating bills are all starting to land on our doormat. Throw in some crappy weather and the fact everybody is talking about how miserable they are - because the media tells them they are - and it all starts to seem plausible that a Monday in mid-to-late January might be the most miserable day.
The story only began circulating in 2005 – which historians will note was several years after the invention of January, Christmas, credit cards and weather - when a PR agency representing Sky Travel seized upon a notion which seemed plausible and worked with psychologist Cliff Arnall to publicise a magic formula that proves this hunch is actually scientific fact.
Sky Travel was obviously keen on seeing its name plastered all over the media and wanted it to be in connection with a story that might make people think they need to cheer themselves up - perhaps by booking a holiday.
Who knows how many extra holidays they may have sold as a result, but in terms of coverage generated it's certainly fair to say the idea worked - so much so this made up day has become a fixture in the UK's news calendar.
Not everybody is impressed though. In 2006, The Guardian's Dr Ben Goldacre branded Cliff Arnall "the most prodigious of all producers of bogus equations", though even his employer has been known to join in the 'Blue Monday' bunfight.
The part of Sky Travel in all of this has long since taken a backseat and the existence of 'Blue Monday' has simply become fact in the minds of media and the many brands and PR agencies who look to capitalise upon it each year. The source is often reduced to unnamed "psychologists" or the catch-all "according to experts" while headlines and standfirsts try to convince us it's all very "official".