“ DEFINITION.—In this subparagraph, the term ‘applicable monthly guarantee’ means— `` (I) for an employee described in clause (i) other than an employee on reserve status, the minimum number of hours for which an employer has agreed to schedule such employee for any given month; and `` (II) for an employee described in clause (i) who is on reserve status, the number of hours for which an employer has agreed to pay such employee on reserve status for any given month, ``as established in the applicable collective bargaining agreement or, if none exists, in the employer's policies. ”

“ CALCULATION OF LEAVE FOR AIRLINE FLIGHT CREWS.—The Secretary may provide, by regulation, a method for calculating the leave described in paragraph (1) with respect to employees described in section 101 (2) (D) . ”