There is an explanation and it might be a little bit antiquated, but basically the final divorce does not occur on that date. If the Judge find the facts support the true breakdown of the marriage and approves that agreement; that Order would be entered right away. Thirty (30) days after the Order is entered, usually that is the date of the Hearing, and a Judgment of Divorce Nisi is issued. However, that Judgment of Divorce Nisi becomes an absolute Judgment of Divorce after ninety (90) days.
So if you seek a divorce with a Joint Petition, it is not final for at least 120 days. However, there is another part with the Massachusetts divorce, if they entered a Judgment Nisi, it becomes 90 days from the entry unless the court so orders, but that generally is harder to get a court date to occur you have to have a longer waiting period to get a court date. So essentially it is either 90 or 120 days after the Agreement is approved before the divorce is absolute. The Judgment Absolute actually terminates the marital relationship.