Britons should have plenty to smile about on Friday, 19 June - as it's officially the happiest day of 2009.
Our spirits have apparenty been boosted by the sunny start to summer, the longest days of the year, the nearing of payday - and optimism that Andy Murray could win Wimbledon.
Psychologist Dr Cliff Arnall devised a formula to pinpoint the day we are all most likely to feel the happiest.
And the Cardiff University lecturer said people should forget credit crunch worries because the secret of happiness lies with things which are free.
Dr Arnall, 44, said feel-good sensations are enjoying time with friends and loves ones, appreciating nature in the sunshine and looking forward to the weekend and a holiday.
His complicated mathematic formula is: O + (N x S) + Cpm/T + He.
O = being outdoors and outdoor activity, N = nature, S = social interaction, Cpm = memories of childhood summers and other positive thoughts, T = temperature, and He = excitement about holidays.
Dr Arnall, from Brecon in Powys, said: "The most important things you can do to be happy are free. People may be less able to afford other leisure activities but it's free to walk in the park or paddle in a stream.
"It refreshes you and you forget your other worries. And the most important thing in our lives are our relationships - and no amount of money can buy that.
"I've spoken to miserable multi-millionaires and people who have no money but are very happy because they have amazing friends."
Our spirits have apparenty been boosted by the sunny start to summer, the longest days of the year, the nearing of payday - and optimism that Andy Murray could win Wimbledon.
Psychologist Dr Cliff Arnall devised a formula to pinpoint the day we are all most likely to feel the happiest.
And the Cardiff University lecturer said people should forget credit crunch worries because the secret of happiness lies with things which are free.
Dr Arnall, 44, said feel-good sensations are enjoying time with friends and loves ones, appreciating nature in the sunshine and looking forward to the weekend and a holiday.
His complicated mathematic formula is: O + (N x S) + Cpm/T + He.
O = being outdoors and outdoor activity, N = nature, S = social interaction, Cpm = memories of childhood summers and other positive thoughts, T = temperature, and He = excitement about holidays.
Dr Arnall, from Brecon in Powys, said: "The most important things you can do to be happy are free. People may be less able to afford other leisure activities but it's free to walk in the park or paddle in a stream.
"It refreshes you and you forget your other worries. And the most important thing in our lives are our relationships - and no amount of money can buy that.
"I've spoken to miserable multi-millionaires and people who have no money but are very happy because they have amazing friends."