# File lib/runt/pdate.rb, line 39
      def + (n)
        raise TypeError, 'expected numeric' unless n.kind_of?(Numeric)
        case @date_precision
        when YEAR then
          return DPrecision::to_p(PDate::civil(year+n,month,day),@date_precision)
        when MONTH then
          current_date = self.class.to_date(self)
          return DPrecision::to_p((current_date>>n),@date_precision)
        when DAY then
          return new_self_plus(n)
        when HOUR then
          return new_self_plus(n){ |n| n = (n*(1.to_r/24) ) }
        when MIN then
          return new_self_plus(n){ |n| n = (n*(1.to_r/1440) ) }
            when SEC then
          return new_self_plus(n){ |n| n = (n*(1.to_r/86400) ) }
      end
    end