law: 23. In section 54 of the principal Act,
  (a) in sub-section (8), in clause (a), for the words "zero-rated supplies", the words "export" and "exports" shall respectively be substituted;
  (b) in the Explanation, in clause (2),
  (i) in sub-clause (c), in item (i), after the words "foreign exchange", the words "or in Indian rupees wherever permitted by the Reserve Bank of India" shall be inserted;
  (ii) for sub-clause (e), the following sub-clause shall be substituted, namely:
  "(e) in the case of refund of unutilised input tax credit under clause (ii) of the first proviso to sub-section (3), the due date for furnishing of return under section 39 for the period in which such claim for refund arises;".