"Sec. 286. When vacation leave and sick leave may be taken. � Vacation leave and sick leave shall be cumulative and any part thereof which may not be taken within the calendar year in which earned may be carried over to the succeeding years, but whenever any officer, employee, or laborer of the Government of the Philippines shall voluntarily resign or be separated from the service through no fault of his own, he shall be entitled to the commutation of all accumulated vacation and/or sick leave to his credit; Provided, That the total vacation leave and sick leave that can accumulate to the credit of any officer or employee shall, in no case, exceed ten months: Provided, further, That the proper Department Head may in his discretion authorize the commutation of the salary that would be received during the period of vacation and sick leave of any appointed officer or employee or teacher or laborer of the Philippine Government and direct its payment on or before the beginning of such leave from the fund out of which the salary would have been paid: Provided, furthermore, That no person whose leave has been commuted following his separation from the service shall be reappointed or reemployed under the Government of the Philippines before the expiration value of the unexpired portion of the leave commuted."