(1) The appropriate Government may, by rules,--
         (a) fix the number of hours of work which shall constitute a normal working day for a building worker, inclusive of one or more specified intervals;
         (b) provide for a day of rest in every period of seven days which shall be allowed to all building workers and for the payment of remuneration in respect of such days of rest;
         (c) provide for payment of work on a day of rest at a rate not less than the overtime rate specified in section 29.
     (2) The provisions of sub-section (1) shall, in relation to the following classes of building workers, apply only to such extent, and subject to such conditions, as may be prescribed, namely:--
         (a) persons engaged on urgent work, or in any emergency which could not have been foreseen or prevented;
         (b) persons engaged in a work in the nature of preparatory or complementary work which must necessarily be carried on outside the normal hours of work laid down in the rules;
         (c) persons engaged in any work which for technical reasons has to be completed before the day is over;
         (d) persons engaged in a work which could not be carried on except at times dependant on the irregular action of natural forces.