Nunc pro tunc (English translation: "now for then") is a Latin expression legal term originating in Great Britain, now in common use in other countries.
[3] Nunc pro tunc may apply also to acts that are allowed after the legally-allotted time to do them has passed.
For example, in the probate of an estate, if property, such as lands, mineral interests, etc., are discovered after the final decree or order, a nunc pro tunc order may include the discovered lands or assets into the estate and clarify how they were meant to be distributed.
[7] Inserting the phrase "nunc pro tunc" or similar arguments on a return or other document submitted to the IRS has no legal effect.
A nunc pro tunc may be signed even after the trial court loses its plenary power.