The study's authors had a look at how retirees spend their time — and not the poor broke retirees we keep hearing about, either; they surveyed the top 20 activities of middle- and high-income retirees, who surprisingly spent much of their time doing things that don't cost a lot of money.

The conclusion? Maybe people don't need to worry quite so much about the amount of money they have saved for retirement. 

While results varied according to demographics, the authors of the study suggested that "financial planners should ask their clients about leisure and household production activities when discussing retirement plans with their clients as a way to account for differences in time allocation."

Those planners or advisors will most likely discover that retirees tend to opt for more "time-intensive" household commodities — home-cooked meals and lovely gardens among them — than "goods-intensive" commodities, i.e., paying somebody else to cook and to grow the flowers (and maybe the fresh veggies for those meals).

Data from the U.S. Bureau of Labor Statistics' 2010-2012 American Time Use Surveys provided the opportunity "to examine the time allocation of middle- and high-income retirees," the study said. None of the retirees had less than $60,000 in household income.

Compared to full-time workers, retirees' top activity was no activity: sleeping, spending 521 minutes in sleep vs. 461 minutes for people still on the job.

Retirees also spent more time eating and drinking, less time on grooming (no more power suits), spent more than twice as much time reading, watched more TV and movies, and five times as much time in the garden as people still working full-time jobs. They also spent more time cleaning the house and cooking meals.

While they also spent more time shopping and playing golf — not exactly cheap activities — overall, they spent an average of 153 minutes more per day on inexpensive activities.