under section 8(a)(2) as appropriate for coverage under this Act (referred to in this Act as a retail, food service, cleaning, or Secretary's designated employee )— (1) for at least 4 hours at the regular rate of pay of the employee involved for each day on which the retail, food service, cleaning, or Secretary's designated employee reports for work, as required by the employer, but is given less than four hours of work, except that if the employee's scheduled hours for a day are less than 4 hours, such employee shall be paid for the scheduled hours of the employee involved for that day if given less than the scheduled hours of work