The relationship between work hours and subjective well being is marked by contradictory findings, thereby implying that it is far from being completely understood. A study of moderator effects can help explain variations in results across studies and, thus, overcome inconsistencies in past research. Accordingly, the current study aims to enlighten the relationship between work hours and well being by investigating how a number of variables moderate this relationship. To develop the research hypotheses concerning the moderator effects, this study relies mostly on social identity theory. Overall, the results suggest that work hours, per se, do not have a significant relationship with individual well being. Rather, their effects seem to depend on a number of issues, namely concerned with individuals' objective characteristics, as well as their social identities.