In this Act, references to time of day are references to Indian Standard Time being five and a half hours ahead of Greenwich Mean Time:
     Provided that for any area in which the Indian Standard Time is not ordinarily observed, the State Government may make rules--
         (a) specifying the area;
         (b) defining the local mean time ordinarily observed therein; and
         (c) permitting such time to be observed in all or any of the plantations situated in that area.