https://www.nber.org/papers/w13837
The Increase in Leisure Inequality
This paper examines the changing allocation of time within the United States that has occurred between 1965 and 2003-2005. We find that the time individuals have allocated to leisure has increased in the U.S. for both men and women during this period, with almost the entire gain occurring prior to 1985. We also find that post 1985 there has been a substantial increase in leisure inequality, particularly for men. Over the last 20 years, less educated men increased the time they allocated to leisure while more educated men recorded a decrease in leisure time. While the relative decline in the employment rate of less educated men is important, trends in employment status explain less than half of the increase in the leisure gap.
Down about 100 hours per year from 1970. I like the idea of quantifying stress but that is probably too subjective to quantitatively measure. I don't necessarily dispute the notion that stress has increased over the past few decades - just that whatever pressure people are feeling is due to declining quality of life or economic opportunity.