Economic evaluations carried out from a societal perspective ought to account for the opportunity cost of a range of resources, including those committed by care recipients. People's time is such a resource: it is limited, valuable and it has an opportunity cost that should be reflected in cost calculations. Yet, when it comes to children and young people (CYP), there are few suggestions on how to value their time and include it in economic evaluations. Despite repeated calls for research, this remains a persistent gap in our methodology "playbook". In this paper, we look at the topic by bringing together seminal literature and recent research findings. We discuss key uncertainties that need to be resolved for the topic to move forwards, outline challenges and "frequently asked questions", offer our views on possible answers and solutions, and sketch out a roadmap for future research.