Over the past several years, many studies have highlighted the strategic nature of working hours, the way they are determined, their regularity and their predictability to judge the qualities of a job and how family life and work life are reconciled. Our results confirm those obtained by previous studies and clarify them, while also showing that both the working hours of the persons questioned and those of their spouse constitute a central variable. We will first review the results from the available French studies and then demonstrate how couples' working hours influence their work-life balance satisfaction.