at the time of hiring of the average number of hours per day that the employee would normally be scheduled to work. (D) Guidelines Not later than 15 days after the date of the enactment of this Act, the Secretary of Labor shall issue guidelines to assist employers in calculating the amount of paid sick time under subparagraph (A). (E) Reasonable notice After the first workday (or portion thereof) an employee receives paid sick time under this Act, an employer may require the employee to follow reasonable notice procedures in order to continue receiving such paid sick time. 5111. Regulatory authorities The Secretary of Labor shall have the authority to issue regulations for good cause under sections 553(b)(B) and 553(d)(A) of title 5, United States Code— (1) to exclude certain health care providers and emergency responders from the definition of employee under section 5110(1) including by allowing the employer of such health care providers and emergency responders to opt out