Retrospective amendment to excise notification validates past actions, bars certain recoveries and allows refunds with time limit. The amendment declares the excise notification to be retrospectively amended for 21 February 2000 to 28 February 2003, validates actions taken under that notification as if the amendment had always been in force, deems the Central Government to have had retrospective power to make the amendment, bars recovery of uncollected duties or those subject to demand or recovery proceedings, and provides for refunds of duties collected contrary to the amended position, subject to Act limitations and a one month refund claim period after presidential assent.