Revision time limit established for tax revisions, excluding rehearing and court stay periods, with appellate-effect exception. Amendment adds subsections to section 20 requiring that orders on revision applications be passed within one year from the end of the financial year in which the application is made, excluding time taken for a re hearing opportunity and periods when proceedings are stayed by court order; it also allows revision orders to be made at any time to give effect to findings or directions of the Appellate Tribunal, the High Court or the Supreme Court.