law: 20. Compensatory day of rest.
  Where, as a result of any exemption granted to an employer under the provisions of this Act from the operation of section 19, a motor transport worker is deprived of any of the days of rest to which he is entitled under that section, the motor transport worker shall be allowed within the month in which the days of rest are due to him or within two months immediately following that month, compensatory days of rest of equal number to the days of rest so lost.