law: Industrial Disputes Act, 1947
  19.Period of operation of settlements
  
  and awards
  (1) A settlement 110[* * *] shall come into operation
  
  on such date as is agreed upon by the parties to the dispute, and if no date is
  
  agreed upon, on the date on which the memorandum of the settlement is signed by
  
  the parties to the dispute.
  (2) Such settlement shall be binding for such period as is
  
  agreed upon by the parties, and if no such period is agreed upon, for a period
  
  of six months 104[from the date on which the memorandum of
  
  settlement is signed by the parties to the dispute], and shall continue to be
  
  binding on the parties after the expiry of the period aforesaid, until the
  
  expiry of two months from the date on which a notice in writing of an intention
  
  to terminate the settlement is given by one of the parties to the other party
  
  or parties to the settlement.
   111  [(3) An award shall, subject to the provisions of this
  
  section, remain in operation for a period of one year 112[from the
  
  date on which the award becomes enforceable under section 17A]:
  PROVIDED  that the appropriate government may reduce the
  
  said period and fix such period as it thinks fit:
  PROVIDED FURTHER  that the appropriate government, may, before
  
  expiry of the said period, extend the period of operation by any period not
  
  exceeding one year at a time as it thinks fit so, however, that the total
  
  period of operation of any award does not exceed three years from the date on
  
  which it came into operation.
  (4) Where the appropriate government, whether of its own motion
  
  or on the application of any party bound by the award, considers that since the
  
  award was made, there has been a material change in the circumstances on which
  
  it was based, the appropriate government may refer the award or part of it 113[to
  
  a Labor Court, if the award was that of a Labor Court or to a Tribunal, if the
  
  award was that of a Tribunal or of a National Tribunal], for decision whether
  
  the period of operation should not, by reason of such change, be shortened and
  
  the decision of 114[Labor Court or the Tribunal, as the case may be]
  
  on such reference shall 115[* * *] be final.
  (5) Nothing contained in sub-section (3) shall apply to any
  
  award which by its nature, terms or other circumstances does not impose, after
  
  it has been given effect to, any continuing obligation on the parties bound by
  
  the award.
  (6) Notwithstanding the expiry of the period of operation under
  
  sub-section (3), the award shall continue to be binding on the parties until a
  
  period of two months has elapsed from the date on which notice is given by any
  
  party bound by the award to the other party or parties intimating its intention
  
  to terminate the award.
   116  [(7) No notice given under sub-section (2) or sub-section
  
  (6) shall have effect, unless it is given by a party representing the majority
  
  of persons bound by the settlement or award, as the case may be.]