PLSQL月份英文

但如果PLSQL版本是中文的话，显示的不是英文而是“*月”

SELECT TO_CHAR(LAST_DAY(SYSDATE), 'yyyy-MON-dd') "本月最后一天" FROM DUAL;
--MON,DD.YYYY
SELECT TO_CHAR(TO_DATE('12-01-49', 'DD-MM-YY'), 'YYYYMMDD') "Year",
       TO_CHAR(TO_DATE('12-01-98', 'DD-MM-YY'), 'YYYYMMDD') "Year",
       TO_CHAR(TO_DATE('12-01-98', 'DD-MM-YY'), 'YYYY/MON/DD') "Year"
  FROM DUAL;
SELECT TO_CHAR(LAST_DAY(SYSDATE), 'MON,dd.yyyy') AS "MEndTime" FROM DUAL