# File lib/rufus/scheduler.rb, line 438
    def occurrences(time0, time1, format=:per_job)

      h = {}

      jobs.each do |j|
        os = j.occurrences(time0, time1)
        h[j] = os if os.any?
      end

      if format == :timeline
        a = []
        h.each { |j, ts| ts.each { |t| a << [ t, j ] } }
        a.sort_by { |(t, _)| t }
      else
        h
      end
    end