FASB 87 and end of year valuations

[FAPInJax]

I have an EOY valuation for funding and FASB 87 purposes. Assuming that the only decrements considered are interest and mortality - how is the service cost and PBO calculated??

The reason for the question has to do with the presentation of information for FASB purposes.

IF I run the valuation as of the beginning of the year (with perfect foresight - knowing what the compensation will be for the upcoming year) versus and end of year valuation - my service cost and accrued benefit at the start of the year are equal. However, the present values are computed one year apart.

Is it acceptable to present the service cost for an end of year valuation equal to the present value using interest and mortality (at valuation date) and have no interest adjustment to year end?? OR must the benefit be valued at the beginning of the year with interest and mortality and then brought forward with interest ONLY to the end of the year?? (You would obviously get 2 different numbers and I required all my old clients to have beginning of the year valuations so never got into the issue)

Again, any help is appreciated. Thanks in advance.