; disaster area The terms federally declared disaster and disaster area have the meanings given such terms under section 165(i)(5). (B) Applicable disaster date The term applicable disaster date means, with respect to any federally declared disaster, the date on which such federally declared disaster occurs. (4) Special rules (A) Application to joint returns For purposes of paragraph (1), in the case of a joint return for a taxable year which includes the disaster date— (i) such paragraph shall apply if either spouse is a qualified individual, and (ii) the earned income of the taxpayer for the preceding taxable year shall be the sum of the earned income of each spouse for such preceding taxable year. (B) Uniform application of election Any election made under paragraph (1) shall apply with respect to both section 24(d) and this section. (C) Errors treated as mathematical error For purposes of section 6213, an incorrect use on a return of earned income pursuant to paragraph (1) shall be treated as a mathematical or clerical error. (D) No effect on determination of gross income, etc Except as otherwise provided in this subsection, this title shall be applied without regard to any substitution under paragraph (1). . (b) Child tax credit Section 24(d) of the Internal Revenue Code of 1986 is amended by inserting after paragraph (2) the following new paragraph: (3) Special rule for determining earned income of taxpayers affected by federally declared disasters For election by qualified individuals with respect to certain federally declared disasters to substitute earned income from the preceding taxable year, see section 32(n). . (c) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2011. 112. Increase in rehabilitation credit for buildings in 2012, 2013, 2014, and 2015 disaster areas (a) In general Section 47 of the Internal Revenue Code of 1986 is amended by adding at the end the following new subsection: (e) Special rule for expenditures made in connection