"Futurama"'s 7:00 p.m. Sunday timeslot caused the show to often be pre-empted by sports and usually have a later than average season premiere. It also allowed the writers and animators to get ahead of the broadcast schedule so that episodes intended for one season were not aired until the following season. By the beginning of the fourth broadcast season, all the episodes to be aired that season had already been completed and writers were working at least a year in advance.