Time limit for completion of assessment restructured, shortening assessment and reassessment timelines and setting procedural extensions. The provision restructures limitation periods: regular assessments are limited to twenty one months from the end of the assessment year of first assessable income; assessments, reassessments and recomputations following a notice are limited to nine months from the end of the financial year in which the notice was served; fresh assessments consequent to orders setting aside or cancelling assessments are to be completed within nine months from the end of the financial year in which such revisional or appellate orders are received or passed. It prescribes short timelines for giving effect to appellate and revisional orders, specifies exclusions from computation of limitation, and contains transitional rules for matters pending at commencement.