Excavations shall be confined to the work described in the permits issued therefor as described in Section 13.12.200. Each permittee shall notify the public works director or his/her duly authorized representative when excavation under the permit will be commenced, and such notice shall be given at least eight working hours before such time of commencement, it being understood that the working hours are between eight a.m. and five p.m. from Monday to and including Friday of each week, excepting legal holidays. (Ord. 1970 NCS § 3 (part), 1994; Ord. 1369 NCS §2 (part), 1979.)