Section 19(1) in The Industrial Disputes Act, 1947
(1)A settlement [* * *] [ The words " arrived at in the course of a conciliation proceeding under this Act" omitted by Act 36 of 1956, Section 14 (w.e.f. 7.10.1956)] 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.