The recipient's service obligation under an award shall be for a period of 24 months. Such service obligation shall consist of either the establishment of a practice of medicine or employment as a licensed physician in the designated shortage area in New York State, or a combination of both. Such practice or employment shall provide full-time direct patient care to the residents of the shortage area. Only periods of service occurring after the receipt of an award payment shall be counted toward fulfillment of the service requirement. Should it be necessary for the recipient to interrupt his or her practice of medicine or employment as a licensed physician, the recipient may apply to the president for a leave of absence. Such application shall be in such form as the president may prescribe and shall state the period for which such leave is requested and the reasons for such leave. The granting of any leave shall be in the sole judgment and discretion of the president.