code: public boolean repeatsMonthlyOnDayCount() {
          if (this.freq != MONTHLY) {
              return false;
          }
  
          if (bydayCount != 1 || bymonthdayCount != 0) {
              return false;
          }
  
          if (bydayNum[0] <= 0) {
              return false;
          }
  
          return true;
      }
docs: Determines whether this rule specifies a simple monthly rule by weekday, such as
  "FREQ=MONTHLY;BYDAY=3TU" (the 3rd Tuesday of every month).
  <p/>
  Negative days, e.g. "FREQ=MONTHLY;BYDAY=-1TU" (the last Tuesday of every month),
  will cause "false" to be returned.
  <p/>
  Rules that fire every week, such as "FREQ=MONTHLY;BYDAY=TU" (every Tuesday of every
  month) will cause "false" to be returned.  (Note these are usually expressed as
  WEEKLY rules, and hence are uncommon.)
  
  @return true if this rule is of the appropriate form