(1) The utility may declare a difficult day or a restricted capacity day and instruct the affected shipper, bulk customer or distribution company by issuing an operational flow order.

(2)A shipper, registered at an entry point or a bulk customer or distribution company registered at an off-take point shall, comply with an operational flow order as soon as reasonably practicable and within

(a) six hours if the operational flow order is issued on Day D-l;

(b) three hours if the operational flow order is issued after 18:00 hours on DayD-1; and

(c) one hour if the operational flow order is issued on Day D.