In Minneasota he has 60 days from the date or the order to file for an appeal. Further the purpose of an appeal is to make sure the lower court's decision applied the correct law when it rendered its decision. This means that if there was a mistaken in law, it does not necessary reverse the decision of custody; rather it makes sure that the lower court applies the law and local rules accordingly. But to answer your question he has 60 days to file an appeal. You can read about the appeal process here.

Rule 104 (page 11) discusses the 60 days required for an appeal.

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