Tax determination procedures require exclusion of stayed periods and limit demands to the grounds in notice. Provisions require exclusion of periods of judicial stay when computing reassessment limitation periods; where a fraud-based notice is unsustainable, the proper officer shall assess tax under ordinary reassessment provisions. Appellate directions must be implemented within two years. An opportunity of hearing must be granted, adjournments allowed for sufficient cause but limited in number, and orders must state facts and reasons. Demands cannot exceed notice grounds; interest on short-paid tax is payable irrespective of mention in the order. Modification of tax by appellate authorities adjusts interest and penalty, unpaid self-assessed tax is recoverable under recovery provisions, and duplicate penalties are barred.