All City offices and legal and official proceedings under the control of the City shall be determined and regulated by the official standard of time in effect throughout the State, and when by ordinance, resolution or action of Council, or action of any City officer, board or body, an act must be performed at or within a prescribed time, it shall be so performed according to such standard of time. All clocks maintained in or upon all public buildings in and under the custody and control of the City shall be set and run according to the provisions of this section.