Wasn't as happy as I would have liked it, since I had no internet connection to actually post this article for your, but the day was all in all good.
And as for the post, better late than never.
So, did you feel especially happy yesterday? It may be that the equation for 24 hours of happiness worked in your favor. It was created by a British psychologist, and it takes into account temperature, summer socialization and more.
You know, these "calculations" are a little arbitrary, in a sense (I mean, what if your seasons are completely different from the western world's?). I had a long day full of boring work, it was about 95 degrees, I was PMS'ing...of course it wasn't the happiest day of the year for me! :)