No blast operations shall be conducted within the City except on weekdays, which are not otherwise legal holidays or Sundays, and only then between the hours of 9:00 a.m. and 4:30 p.m. However, in the event the City Seismologist and the Safety Director agree that an emergency situation exists, such hours and times of blasting may be specifically varied to counteract such emergency. (Ord. 32-1975. Passed 3-24-75.)