Overtime fee: customs services beyond prescribed working hours attract per hour charges and minimum block billing. Overtime fee applies when Customs officers perform Customs functions outside prescribed duty hours, on holidays, or at locations other than their normal place of work; the Commissioner's prescribed working hours determine levy applicability. Fees vary by officer category and time band, are subject to a three hour minimum (with exceptions for immediate pre/post duty postings), and treat midnight-6 am as a single chargeable block; services beyond the Customs area during working hours are charged for the entire relevant pre or post lunch block whether used wholly or partly.