“Extended service period” means a period of time commencing on the extended service calculation date and ending (a) on the date of the judge’s retirement or his or her earlier termination of service, as provided in subdivision (b) of Section 75086.1, or (b) 120 months after the extended service calculation date, whichever is earlier. Nothing in this article shall be deemed to prohibit a judge from continuing to perform creditable service beyond the extended service period.