(a) During Plenary-Power Period. If a judgment is modified in any respect while the trial court retains plenary power, a period that, under these rules, runs from the date when the judgment is signed will run from the date when the modified judgment is signed.
(b) After Plenary Power Expires. If the trial court corrects or reforms the judgment under Texas Rule of Civil Procedure 316 after expiration of the trial court’s plenary power, all periods provided in these rules that run from the date the judgment is signed run from the date the corrected judgment is signed for complaints that would not apply to the original judgment.