Day worked as a male model and appeared in several television commercials. This led to guest roles in episodes of
Skippy the Bush Kangaroo,
police dramas
The Link Men,
The Long Arm,
Homicide and
Matlock Police produced by
Crawford Productions. This culminated in the regular role of Senior Detective Phillip Redford in Crawford's series
Homicide in 1973. Redford was a university graduate who had served as a bomb disposal expert in Vietnam, and was anti-violence as a result. Day was the only cast member who appeared in all colour episodes of
Homicide until it ceased production in 1975. Following this he appeared as a regular in Crawford's
soap opera The Box as Marcus Boyd in 1977. His other regular series role was as Detective Inspector Malcolm Thorne in
Murder Call in 1997–98. Guest roles include
Cop Shop, ''
Carson's Law, Blue Heelers, Halifax f.p., Dogs Head Bay''. == Stage roles ==