A large body of literature has examined the effect of parental employment--primarily maternal employment--on the amount of time spent with children and in childcare activities, and it is well documented that employed parents spend less time with their children than nonemployed parents. But not all time is equal. Research on circadian rhythms suggests that children’s ability to benefit from parents’ enriching childcare activities, such as reading to and playing with their children, varies by time of day. Thus, we would expect parents to engage in these enriching activities at times of day when it is the most valuable to their children. If employment causes parents to shift their childcare activities away from times when it is the most valuable, then differences in the amount of time that employed and nonemployed parents spend in childcare underestimate the effect of employment on parents’ quality-adjusted time with their children. In this study, we examine whether employment results in parents shifting the time spent engaging in childcare activities to times that may be less productive. We develop a simple model of timing that predicts that parents will spend more time with their children when it is most productive. We then use data from the American Time Use Survey to compare workdays to nonwork days, and find that employment significantly affects the timing of enriching childcare activities for both mothers and fathers who are employed full time. In particular, these parents shift enriching childcare activities into the evening hours. In contrast, part-time employment has a much smaller effect on when mothers spent time with their children. Thus, part-time employment not only allows mothers to spend more time with their children compared to full-time employment, it also allows them to spend that time when it may be the most beneficial and enjoyable.