Subsection (1) of section twenty-four of the Finance Act, 1947 (which allows relief from income tax and the profits tax for certain capital expenditure on rehabilitation), shall have effect as if in the proviso thereto (which, as set out in section thirty-three of the Finance Act, 1948, extends in certain cases till not later than the end of March, nineteen hundred and fifty-two, the period within which the expenditure must have been incurred if the relief is to be given) for the words "the end of March, nineteen hundred and fifty-two," there were substituted the words " the end of March, nineteen hundred and fifty-four. "