It's dictum from an
unpublished case, but it outlines the basic principle that the other spouse's
share of retirement benefits is calculated as of the date of separation:
However, there is a difference between determining the spouse's share and determining the value of that share. See
In re Marriage of Monbrun (another unpublished case, but with citations to the published authority),
If you can establish to the satisfaction of the court that the MSA includes an agreement that the date of valuation is the date of separation, the court should uphold your agreement. If not, your wife can certainly argue for the later valuation date.