For the purpose of this paragraph, an employee is considered to have retired before his/her first pay period beginning after June 30, 1960, if his/her annuity began to accrue before his/her first pay period after June 30, 1960, or if he/she was eligible under paragraph (d) of this section until the date his/her annuity began to accrue.
5 C.F.R. §891.103