We examine the determinants of time allocation and child labour in a year-long panel of time-use data from colonial Nigeria. Using quantitative and ethnographical approaches, we show that health shocks imposed time costs on individuals. Whether individuals could recruit substitutes depended on social standing, urgency of work, and type of illness. Child labour did not systematically respond to temporary parental illness, but could replace a permanently disabled adult. Child labour was coordinated with parental work, aided childcare, and allowed children to build skills and resources. These decisions can be understood within an endogenous bargaining power framework with labour complementarities.