Does a coverture fraction always use time as its benchmark to determine the marital portion?

No. In some cases measuring the period of time the employee participated in the plan against the total period of time the employee was a participant in the plan as of the cut-off date does not provide an accurate picture of the benefits which were accumulated during the marriage. Based upon the mechanics of the plan itself, it may be more appropriate to use contributions or actual service credit, instead of months or years. For instance, military reserve members receive a pension based upon the number of points earned during their service with the reserves. Due to the nature of being a reservist, more points may be earned in one year than was earned in another. Therefore, a coverture based upon the number of points earned during the marriage would provide a much better picture of the marital property portion of the benefits than just using the number of years the parties were married in the coverture.