This paper presents the distinct and changing roles of the transitions and durations of marriage and parenthood in shaping gendered time-use patterns. Using harmonized British Household Panel Survey (BHPS) and the UK Household Longitudinal Study (UKHLS) (1992-2017), the results from fixed-effect linear regressions show that, soon after marriage, women’s housework time and men’s paid work time increase. As marriage continues, women’s paid work time and men’s housework time decrease, thereby enhancing traditional gender roles. Both women and men reduce paid work time and increase housework time to cope with the arrival of a child. As the child grows up, mothers’ paid work time increases, and their housework time decreases, whereas fathers’ time allocation remains stable. The much more substantial shift to the caregiver role for women than for men drives the strong traditionalizing role of parenthood. Over the last 25 years, the traditionalizing role of motherhood has weakened, and the traditionalizing role of marriage has disappeared for women in the 2010s. However, the association between time allocation and family formation has changed little among men, implying that the “second half” of the gender revolution has made little progress in Great Britain.