Day, credited with helping women break into TV production, lost her battle with cancer on 23 October (09) in Georgetown, Texas, according to Daily Variety.
Throughout a long career in Hollywood, she directed more than 350 episodes of small-screen hits including long-running soap opera Dallas, Married With Children, Mad About You, The Nanny and Who's The Boss?
She received an Emmy Award nomination for her work on Archie Bunker's Place and was recently honoured by the Directors Guild of America as a pioneer for women working in TV.
She is survived by her husband, L. Steve Varnum, a daughter and a sister.