(a) General rule. For the purpose of determining the days of service
which must be credited to an employee for a computation period, a plan
shall determine days of service from records of days worked and days for
which payment is made or due. Any records may be used to determine days
of service to be credited to employees under a plan, even though such
records are maintained for other purposes, provided that they accurately
reflect the actual number of days of service with which an employee is
required to be credited under Sec. 2530.200b-7(a). Payroll records, for
example, may provide sufficiently accurate data to serve as a basis for
determining days of service. If, however, existing records do not
accurately reflect the actual number of days of service with which an
employee is entitled to be credited, a plan must develop and maintain
adequate records. A plan may in any case credit days of service under
any method which results in the crediting of no less than the actual
number of days of service required to be credited under Sec. 2530.200b-
7(a) to each employee in a computation period, even though such method
may result in the crediting of days of service in excess of the number
of days required to be credited under Sec. 2530.200b-7(a). A plan is not
required to prescribe in its documents which records are to be used to
determine days of service.
(b) Determination of pre-effective date days of service. To the
extent that a plan is required to determine days of service completed
before the effective date of part 2 of title I of the Act (see section
211 of the Act), the plan may use whatever records may be reasonably
accessible to it and may make whatever calculations are necessary to
determine the approximate number of hours of service completed before
such effective date. For example, if a plan or an employer maintaining
the plan has, or has access to, only the records of compensation of
employees for the period before the effective date, it may derive the
pre-effective date days of service by using the daily rate for the
period or the days customarily worked. If accessible records are
insufficient to make an approximation of the number of pre-effective
date days of service for a particular employee or group of employees,
the plan may make a reasonable estimate of the days of service completed
by such employee or employees during the particular period. For example,
if records are available with respect to some employees, the plan may
estimate the days of service of other employees in the same job
classification based on these records. A plan may use the elapsed time
method prescribed under Sec. 2530.200b-9 to determine days of service
completed before the effective date of part 2 of title I of the Act.