The department may, in its discretion, grant sick leave at half pay for personal illness to a permanent employee having not less than a year of service after all of his sick leave credits have been used; provided however, that the cumulative total of all sick leave at half pay granted to any employee after January 2, 1957, shall not exceed one pay period for each complete six months of his State service.
N.Y. Comp. Codes R. & Regs. Tit. 10 § 84.19