SECTION 1. Section nineteen hundred forty-three of the Revised Administrative Code is hereby amended to read as follows:
"SEC. 1943. Allowance and compensation for overtime work and extra pay for night service.-1. When necessary service beyond office hours or upon a holiday is rendered by an employee of the Bureau of Posts upon requirement of the Director of Posts, an equal amount of time may be allowed him on a regular work day, but no accumulation of such time shall be allowed for vacation purposes.
"2. Subject to the approval of the Secretary of Public Works and Communications, the Director of Posts may pay compensation for overtime work rendered by employees of the Bureau, in lieu of compensatory time, such overtime pay to be based on their regular wage or salary. In computing the overtime pay of employees paid on the annual basis, the yearly salary shall be divided by the total number of days during the calendar year which remain after deducting the total number of Sundays and legal holidays and the quotient thus obtained will be the daily compensation which, divided by the present number of working hours in an ordinary work day, will give the hourly compensation for such overtime service.
"3. Employees of the Bureau who are required to perform night work shall be paid extra for such work at the rate of ten per centum of their hourly pay per hour: Provided, That night work is defined as any work done between the hours of six o'clock postmeridian and six o'clock antemeridian."