# File lib/numru/nusdas.rb, line 162
      def str_from_time(time)
        raise("arugment must be String") unless Integer === time
        date = @@date0 + time/(60*24)
        year = date.year
        mon = date.mon
        day = date.day
        i = time%(24*60)
        hour = i/60
        min = i%60
        return  "%4d%02d%02d%02d%02d"%[year,mon,day,hour,min]
      end