19/03/2014 13:15 GMT | Updated 19/05/2014 06:59 BST


Wandering through London last weekend, I spotted a sign outside a pizza restaurant, which read 'Hello Happiness'. I was smiling anyway, thanks to the sun being out and my arms being full of the bundle of gorgeousness that is my niece, Skyla. Still, I smiled a little more. (And not just because the thought of pizza was suddenly an excellent one.)

I can be pretty cynical when it comes to marketing messages, but it feels like happiness is having a moment right now. We know that technically money can't buy happiness, but maybe we're actually beginning to really believe it.

We see photos of the rich and famous sunbathing on their yachts, we speculate about how much industry leaders are being paid, and it just doesn't have the appeal it used to.

As part of HuffPost's Third Metric movement, we're hearing stories from across the globe of individuals placing emphasis elsewhere in their lives. They're prioritising health and happiness over personal gain, and today, on International Day of Happiness, we want to celebrate that.

For the UN, happiness is now recognised as a 'fundamental human goal' and, according to Action for Happiness, an amazing 87% of us would choose happiness and wellbeing over money.

"Marketers and advertisers tell us that happiness comes from buying the right products," Action for Happiness director Mark Williamson told HuffPost UK's lifestyle editor, Poorna Bell.

"Celebrities and the media pretend it comes with beauty and fame. Meanwhile, politicians claim that nothing matters more than growing the economy.

"To celebrate the Day of Happiness 2014, we're asking people around the world to share a genuine vision of happiness, reclaiming it back together from those who would manipulate us."

The things that make us happy are as individual as we are. Certainly, when we asked HuffPost editors from our 11 international editions to send us photos of what made them happy, there wasn't a swanky boat or paycheque in sight. Instead there were sunny skies, trees being climbed and even some baby tortoises.

Today, we're asking you to tweet your own pictures of what makes you happy with the hashtag #happinessday. Our favourites are being published right here.

Today also marks the launch of our new Letting Go series, which will profile people from all four corners of the world, who in their own way, are taking stock of their lives and taking steps to make them simpler, saner and more fulfilling.

Joshua Fields Millburn kicks off the series, a man who knows plenty about letting go, having quit the 80-hour weeks and six-figure salary for a life that now involves just 280 personal possessions and the intriguing website The Minimalists.

Wherever in the world you are, enjoy your own personal Day of Happiness today. If you don't want to tweet your pictures, why not just try a smile. I hear they go viral quicker than a listicle!