def interpret_daymonthly_variant
      hash_for_occ_base = { type: :daymonthly, interval: interval }
      array_of_occurrences = []
      repeats_on.each do |on|
        h = { week_of_month: on[0], day_of_week: on[1] }
        array_of_occurrences << hash_for_occ_base.merge(h)
      end
      array_of_occurrences
    end
def interpret_daymonthly_variant
      hash_for_occ_base = { type: :daymonthly, interval: interval }
      array_of_occurrences = []
      repeats_on.each do |on|
        h = { week_of_month: on[0], day_of_week: on[1] }
        array_of_occurrences << hash_for_occ_base.merge(h)
      end
      array_of_occurrences
    end
repeats_on is an array of arrays: Each sub array has the format
 [week_of_month, day_of_week].  For example,
 "the first and second sat of every month" will produce
 repeats_on == [[1,5], [2,5]]