This question pops up once in a while, mostly when you are muddled up – have you ever thought about it when you were on a dance floor?
Have believed that it would be the happiness quotient of overall timespan, but is that it? How can you be always happy – faking it or really creating that environment? And your environment is people around you. The ones closest (immediate family/spouse) to you do impact your daily happiness in most profound way, but it would be more constructive and worthwhile if you can extend your actions to bring the best out of extended network – community/society/subordinates.
This article sums it up very well, ‘How will you measure your life’, http://hbr.org/2010/07/how-will-you-measure-your-life/
Plan to read the book at earliest.