SECTION 1. Subsections (c) and (e) of Section twelve of Commonwealth Act Numbered One hundred eighty-six, as inserted by Republic Acts Numbered Sixteen hundred sixteen and Six hundred sixty, and as amended by Republic Act Numbered Seven hundred twenty-eight, are hereby further amended to read as follows:
"(c) Retirement is likewise allowed to a member, regardless of age, who has rendered at least twenty years of service. The benefit shall, in addition to the return of his personal contributions plus interest and the payment of the corresponding employer's premiums described in subsection (a) of Section live hereof, without interest, be only a gratuity equivalent to one month's salary for every year of service, based on the highest rate received, but not to exceed twenty-four months. This gratuity is payable by the employer or office concerned which is hereby authorized to provide the necessary appropriation or pay the same from savings in its appropriations. Officials and employees paid gratuity under this subsection shall be entitled to the commutation of the unused vacation and sick leave, based on the highest rate received, which they may have to their credit at the time of retirement."
"(e) Retirement shall be automatic and compulsory at the age of sixty-five years, and optional retirement at the age of sixty-three shall be allowed with lump sum payment of present value of annuity for first five years, and future annuity to be paid monthly, and other benefits given to a compulsory retired member as provided for in Republic Act Numbered Six hundred sixty, as amended, if he has completed fifteen years of service and if he has not been separated from the service during the last three years of service prior to retirement; otherwise he shall be allowed to continue in the service until he shall have completed the required length of service unless he is otherwise eligible for disability retirement. This clause shall not apply to members of the judiciary and constitutional officers whose tenure of office is guaranteed. It shall be the duty of the employer concerned to notify each such employee under its direction of the date of his automatic separation from the service at least sixty days in advance thereof."