law: General Clauses Act, 1897
  5. Coming into operation of enactment
  15[(1) Where any Central Act is not expressed to come into
  
  operation on particular day, then it shall come into operation on the day on
  
  which it receives the assent-
  (a) in the case of a Central Act made before
  
  the commencement of the Constitution, of the Governor-General, and
  (b) in the case of an Act of Parliament, of
  
  the President].
  16[* * * ]
  (3) Unless the contrary is expressed, a 13[Central Act] or
  
  Regulation shall be construed as coming into operation immediately on the
  
  expiration of the day preceding its commencement.