Prof Day has pioneered a range of evidence-based community child and family services, parenting programmes and interventions from pregnancy to adolescence. These include interventions and approaches for community and early intervention (Empowering Parents, Empowering Communities, Day et al., 2012, 2020; Family Partnership Model, Day, Ellis and Harris, 2015; and Antenatal and Postnatal Promotional Guide system (Day, 2014).

Prof Day and his colleagues have developed specialist parenting treatments for parents with severe mental health difficulties and disorders, and child neglect and abuse. Prof Day leads research and development, service provision and dissemination of these internationally recognised parenting programmes and approaches from pregnancy to adolescence. Prof Day works with closely colleagues in China, Japan, Australasia, Europe and the US to implement these programmes in a global context.