(a) The appointing authority shall establish and publish, subject to the approval of the Department of Civil Service, rules and schedules establishing penalties for tardiness. Such penalties shall not preclude disciplinary action in cases of excessive tardiness. In the event of public transportation difficulties, strikes, severe storms or floods, or similar uncontrollable conditions affecting a group of employees, tardiness may be excused by the appointing authority.

(b) The appointing authority may excuse a reasonable amount of tardiness caused by direct emergency duties of duly authorized volunteer ambulance squad members, volunteer firemen, enrolled civil defense volunteers, and enrolled civil air patrol volunteers, subject to whatever evidence of participation in such activities may be deemed necessary by the appointing authority.