# File lib/runt/pdate.rb, line 45
    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 WEEK then
        return new_self_plus(n*7)      
      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) ) }
      when MILLI then
        return self
    end
  end