"For 27 years I have been ship's surgeon aboard the U.S.S. Enterprise."
says Dr. McCoy around Stardate 9522.6.
He first appeared in "Mudd's Women" (Stardate 1329.1), assuming 1.000 digits equal one solar year and after Stardate 9999.9 a new cycle begins, we should have Stardate 8329.1.
Too bad, one year is apparently missing but it's only one year.