# File lib/ice_cube/validations/day_of_month.rb, line 5
    def day_of_month(*days)
      days.flatten.each do |day|
        unless day.is_a?(Integer)
          raise ArgumentError, "expecting Integer value for day, got #{day.inspect}"
        end
        verify_alignment(day, :day, :day_of_month) { |error| raise error }
        validations_for(:day_of_month) << Validation.new(day)
      end
      clobber_base_validations(:day, :wday)
      self
    end