(a) Whenever it shall be determined, subsequent to the dates specified in §§ 3301 and 3303 of this title, that a duly nominated candidate will be unable to serve if elected because of death, physical, mental or other incapacity, the state, county or city (if a municipality holds its election at the time of the general election) committee shall convene within 24 hours of said determination to authorize the filing of a supplemental certificate of nomination for a substitute candidate, or to decline to issue such a certificate. However, in the case of the death of a candidate, said committee may convene within a reasonable period of time sufficient to have the new candidate's name placed on the ballot, but in no case later than 5 days from the date of death.
(b) Such certificate, if issued, shall be delivered to the officer or officers to whom the original certificate was submitted no later than 12: