# File lib/ice_cube/validations/day.rb, line 5
    def day(*days)
      days = days.flatten
      return self if days.empty?
      days.flatten.each do |day|
        unless day.is_a?(Integer) || day.is_a?(Symbol)
          raise ArgumentError, "expecting Integer or Symbol value for day, got #{day.inspect}"
        end
        day = TimeUtil.sym_to_wday(day)
        verify_alignment(day, :wday, :day) { |error| raise error }

        validations_for(:day) << Validation.new(day)
      end
      clobber_base_validations(:wday, :day)
      self
    end