# File lib/ri_cal/occurrence_enumerator.rb, line 229
    def zulu_occurrence_range
      if bounded?
        all = occurrences
        first, last = all.first, all.last
      else
        first = occurrences(:count => 1).first
        last = nil
      end
      [first.zulu_occurrence_range_start_time, last ? last.zulu_occurrence_range_finish_time : nil]
    end