From the late 1950s Day was a popular figure in British movies, a glamorous blonde bombshell who appeared most memorably in the classic Stanley Baker drama Hell Drivers (1957) and the Hammer science fiction film Quatermass 2 (1957). Her other film roles include that of George Cole’s girlfriend in Mario Zampi’s comedy Too Many Crooks (1959) and as the heroine in the horror film Womaneater (1958), one of her few leading parts.