Assessment time limits revised: one-year limit introduced and extension granted where search or requisition is pending. Amendments to section 153 change limitation periods for assessment and reassessment: the transitional nine-month rule is confined to specified assessments while a one-year limit applies for assessments of later years; sub-section (1A) is extended to twelve months. Sub-section (3) and related provisions are broadened to include orders under sections 263 and 264 when passed by Principal Chief Commissioner or Chief Commissioner, and a new sub-section (3A) extends assessment/reassessment periods by twelve months where a search or requisition has been initiated or seized/requisitioned material relates to the assessee. Explanation 1 is amended to include inventory valuation by a cost accountant.