The Futon Critic reported that the three mentioned cancelled shows from the fall 2013 season will be aired every Saturdays this summer beginning in June.
Here are the details:
Zero Hour will return with back-to-back episodes on June 15 at 8/7c on ABC. It will air new episodes each week, leading up to a two-hour finale on Aug. 3.
NBC's Do No Harm will return on June 29 at 10/9c.
TV Line previously reported that ABC will also air the final episodes of 666 Park Avenue on Saturdays this summer, though a return date has not been confirmed.