Advance ruling validity under Customs law extended to five years, with transitional extension for rulings in force on assent. The Customs Act is amended in relation to advance rulings under section 28J by substituting five years for three years in sub-section (2). The proviso is replaced to allow the Authority, on the applicant's request, to extend the validity of any advance ruling in force on the date of presidential assent for five years from the date of the ruling.