Sharif, M., Mogilner, C., & Hershfield, H. (2021). Having too little or too much time is linked to lower subjective well-being. Journal of Personality and Social Psychology, Advance Online Publication, 1-16. https://doi.org/10.1037/pspp0000391.

Abstract
Many people living in modern society feel like they do not have enough time and are constantly searching for more. But is having limited discretionary time actually detrimental? And can there be downsides of having too much discretionary time? In two large-scale data sets spanning 35,375 Americans and two experiments, we explore the relationship between the amount of discretionary time individuals have and their subjective well-being. We find and internally replicate a negative quadratic relationship between discretionary time and subjective well-being. These results show that whereas having too little time is indeed linked to lower subjective well-being caused by stress, having more time does not continually translate to greater subjective well-being. Having an abundance of discretionary time is sometimes even linked to lower subjective well-being because of a lacking sense of productivity. In such cases, the negative effect of having too much discretionary time can be attenuated when people spend this time on productive activities.