Is there any law or case law that states 31-day divorce reversal?

Divorces are governed by the Divorce Act, R.S.C. 1985, c.3. Section 12 of that statute, in part, states that a divorce takes effect on the thirty-first day after the day on which the judgment granting the divorce is rendered.
 
The 31 days may be interrupted by the filing of an appeal.
 
A person is always advised to get a Certificate of Divorce after the divorce takes effect, in accordance with section 12 of the aforesaid statute.