Cal. Fam. Code § 7635.5

In any action brought pursuant to this article, if the alleged father is present in court for the action, the court shall inform the alleged father of the alleged father’s right to have genetic testing performed to determine the biological parentage of the child. The court shall further inform the alleged father of the alleged father’s right to move to set aside or vacate a judgment of parentage pursuant to Section 7646 within two years of the date notice of the action to establish parentage is received, and that after that time has expired the alleged father may not move to set aside or vacate the judgment of parentage, regardless of whether genetic testing shows the alleged father not to be the biological father of the child.