FEELING miserable this morning? Down in the dumps at your desk? Well, you and the rest of the world, because January 15 is supposedly the most depressing day of the year.

A combination of factors conspire to make the third Monday of the year the singularly most despondent. These include the recognition that, yup, Christmas really is over, the realisation of all the money we've spent celebrating it and the fact most of us are back at work.

First coined in Britain, and dubbed "Blue Monday", in the northern hemisphere there's the added misery that January is also deep, dark midwinter.

There's even a complex calculation that some believe proves the January 15 fed-up factor. But others aren't so convinced and think Blue Monday is all baloney.

Post-Christmas has always been a bit of a downer, unless you're on a month-long break relaxing on a beach somewhere of course, but Blue Monday only became a thing back in 2005.

It was then that Dr Cliff Arnall, a lecturer and "freelance happiness guru" from South Wales, dreamt up his gloomy calculation that concluded that the third Monday of January each year was always the most melancholy.

That calculation goes something like this: [W + (D-d)] x Tq ÷ [M x Na]. Uh huh.

'W' stands for weather, 'D' for debt, 'd' refers to the monthly salary, 'T' the time since Christmas, 'q' the period since we've broken our New Year's resolutions, 'M' for motivational levels while 'Na' is the feeling of a need to take action.

If that all sounds a little bit confusing, the general idea seems to be that on this day all the bad stuff in our lives outweighs the good stuff.

Hence, today is a Monday that feels marginally worse than the Tuesday after that massive festival you went to that you remember being the best time of your life but three days later you weren't sure if you had any real friends and thought your life sucked big time. Luckily, things got better by Wednesday.

Still keeping up you New Year’s resolution to go jogging at Bondi every morning? No, neither are we.
Still keeping up you New Year’s resolution to go jogging at Bondi every morning? No, neither are we.

However, do not despair, say psychologists, for Blue Monday was a bit ropy to be perfectly honest and was actually all a marketing ruse. You see, January in the UK is peak holiday booking time and the original research was paid for by a travel agent eager to persuade people to banish the blues by heading to the beach. Preferably through them.

Indeed many psychologists have pooh-poohed the whole idea. University of East London academic Jolanta Burke reckons Blue Monday is only blue because it's become something of a self-fulfilling prophecy.

"When we hold some expectations about an event, people, or ourselves, we start behaving in a way that matches our expectations.

"For example, thinking it is the most depressing day of the year, we might start paying more attention to the negative events around us - the boss who doesn't listen to our good advice, or the partner who isn't doing enough around the house," Ms Burke wrote in The Conversation.

We might also scupper our Monday by, let's say, not going to the gym, making ourselves feel even bluer.

January in Australia doing its best to banish away the post-Christmas blues. Picture: Leonie Minns
January in Australia doing its best to banish away the post-Christmas blues. Picture: Leonie Minns

"While there is no scientific evidence of Blue Monday on the third Monday of January - or any other Monday in a year - research shows us that, unsurprisingly, our mood is significantly better on Fridays and over the weekend in general," she said.

This is generally because we got more sleep and "me time" to indulge ourselves.

Ms Burke said we need to turn that post-Christmas frown upside down and stop moping.

"Since Blue Monday is a hoax that may affect our thinking and emotions so much, let's turn it into Happy Monday and reap the benefits.

"Instead of searching for all that is going badly on the day, be mindful of all the good things that happen around you - that woman who held the bus door to prevent it from closing, the old lady who smiled at you for no reason or the little boy who gave you a big hug."

And of course, living in Australia, we have another thing going for us to banish away those Blue Monday blues. It's glorious midsummer, the days are long and the beers are cold.

Unless you're not a fan of 40C days in which case it really could be a red hot and very Blue Monday.