Years of service
In determining the number of years of service for purposes of this subsection, there shall be included—
(A)#
one year for each full year during which the individual was a full-time employee of the organization purchasing the annuity for him, and
(B)#
a fraction of a year (determined in accordance with regulations prescribed by the Secretary) for each full year during which such individual was a part-time employee of such organization and for each part of a year during which such individual was a full-time or part-time employee of such organization.
In no case shall the number of years of service be less than one.