The day which is known as Blue Monday is calculated using a series of factors in a mathematical formula.

Using the formula it has been calculated that today, January 15, is the most depressing day of the year. The happiest day of the year will be some time during midsummer.

In 2005, psychologist, Dr. Cliff Arnall was asked to create a formula to determine which day of the year would be the most depressing and the happiest.

The formula takes into account weather, debt, the time since Christmas, the time since failing new year’s resolutions, motivational levels and the feeling of a need to take action.

Another date for your calender is December 11, the day you are most likely to be dumped.

5 ways to make your Blue Monday better.

• Watch a feel good film with loved ones.

• Exercise - taking part in a work out will release good endorphins which will naturally improve your mood.

• Take part in a hobby related activity - do something you love and are passionate about.

• Enjoy your favourite meal for dinner.

• Go for a walk and enjoy the fresh air and your surroundings.