Using large longitudinal survey data from the UK Millennium Cohort Study, this paper estimates the effect of maternal time inputs on early child development. We find that maternal time is a quantitatively important determinant of skill formation and that its effect declines with child age. There is evidence of a long shadow of the effect of early maternal time inputs on later outcomes, especially in the case of cognitive skill development. In the case of non-cognitive development, this effect disappears when we account for skill persistence.