We don’t know the number of children meeting (not meeting) these guidelines as they develop across the pre-school years, and the social and demographic factors associated with children obtaining recommended sleep durations (or not). This project will use Growing Up in New Zealand dataset to assess sleep in a large group of New Zealand children and answer key questions: how many NZ children are meeting the MOH guidelines for sufficient good quality sleep over time and what social and demographic factors are associated with NZ children meeting or not meeting the sleep guidelines.