Podfile

post_install do |installer_representation|
  installer_representation.project.targets.each do |target|
    if target.name == 'Pods-MTDates'
      target.build_configurations.each do |config|
        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= ['$(inherited)']
        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] << 'MTDATES_NO_PREFIX=1'
      end
    end
  end
end