The seven-day week, consisting of five work days and two weekend days, has governed our work and home lives for generations but the emergence of the 24/7 service economy has meant that traditional work schedules have become increasingly eroded for many people in recent decades. This paper investigates the extent to which weekend working is a significant determinant of well-being. Using data from Understanding Society (waves 2, 4 and 6), I estimate a fixed effects model to test whether transitions into or out of weekend working over time are associated with changes in subjective well-being. I find that weekend working is associated with reduced satisfaction with leisure time and worse mental health, as measured by the General Health Questionnaire (GHQ), although there is no effect on life satisfaction. My model is repeated using a longitudinal Labour Force Survey (LFS) dataset. This analysis finds that working at the weekend is significantly associated with reduced happiness but there are no effects when looking at anxiety, life satisfaction or eudaimonic well-being. This paper summarises the first chapter of my PhD thesis.