In this subpart-
Full-time service means service performed by an employee who has-
Part-time service means any actual service performed on a less than full-time basis, by an individual whose appointment describes a regularly scheduled tour of duty, and any period of time credited as nonpay status time under 5 U.S.C 8411(d) , that follows a period of part-time service without any intervening period of actual service other than part-time service.
Proration factor means a fraction expressed as a percentage rounded to the nearest percent. The numerator is the sum of the number of hours the employee actually worked during part-time service; and the denominator is the sum of the number of hours that a full-time employee would be scheduled to work during the same period of service included in the numerator. If an employee has creditable service in addition to part-time service, such service must be included in the numerator and denominator of the fraction.
Total service means the full years and twelfth parts thereof of an employee's or Member's service creditable under subpart C of this part, excluding any fractional part of a month.
5 C.F.R. §842.402