An employer shall provide no less than 15 days per calendar year of unpaid Civil Air Patrol leave to an employee responding to an emergency mission of the Maryland Wing of the Civil Air Patrol. An employee shall give the employer as much notice as possible of the intended dates of the beginning and end of leave. After arriving at an emergency location, the employee shall notify the employer with an estimate of the amount of time needed to complete the emergency mission. The employee shall report to the employer necessary changes in the time required to complete the mission. The employer may require verification of the eligibility of the employee for the Civil Air Patrol leave requested or taken. If the employee fails to provide the required certification, the employer may deny the Civil Air Patrol leave. An employee taking leave under this subtitle may not be required to exhaust all available leave before using Civil Air Patrol leave. Nothing in this subtitle prevents an employer from providing paid leave for leave under this subtitle.