How children use their time is critical for their health, emotional, and cognitive development. Studies typically find that parental divorce lowers child development, due to a decline in parents’ monetary and time resources. Yet, little is known on how parental separation affects child time use. This study fills this relevant knowledge gap by using prospective time-diary data from the Longitudinal Study of Australian Children (LSAC), a unique survey following children’s time use across six waves (N = 14,862 observations from 3,719 children). Results from both random and fixed effects models provide four main findings: (i) mother-child time increases dramatically after parental separation, at the expense of children’s time with two parents, while father-child time stays low both before and after parental separation; (ii) after parental separation, children slightly decrease their time in educational activities and increase substantially their time in unstructured activities; (iii) boys’ developmental time use is harmed by parental separation to a higher degree than girls’; and (iv) parents in high socio-economic backgrounds tend to compensate more effectively for the potential negative consequences of divorce by investing more time in children, compared to parents in unprivileged social backgrounds. Our findings have important implications for family policy. Results point to the need of spreading joint custody to improve gender equality in parental childcare time after divorce, as well as promoting greater support for boys and disadvantaged families in dealing with the adverse effects of parental union dissolution on children’s daily routines, development, and life chances.