This is the scheduled clock time (HH:MM) on Sunday at which load bank 3, previously shed earlier that day by disconnect3LoadShedSundayOff, is scheduled to reconnect, per the description. Pairing this reconnect time with disconnect3LoadShedSundayOff defines bank 3's full shed window for Sunday; because bank 3 usually carries the most essential load, this window is typically the shortest of the three banks. A value of '07:00' paired with an Off time of '20:00' on the same Sunday defines that day's full overnight shed window for bank 3; if the On time were set earlier than the Off time, that day's schedule would effectively do nothing.