Date Timezone Oracle PLSQL

SQL>
SQL> SELECT MONTHS_BETWEEN(TO_DATE(TO_CHAR(TO_DATE('&date1'),
  2         'mmyyyy'), 'mmyyyy'),
  3         TO_DATE(TO_CHAR(TO_DATE('&date2'), 'mmyyyy'),
  4         'mmyyyy')) Diff_Date
  5  FROM   DUAL;
Enter value for date1:
old   1: SELECT MONTHS_BETWEEN(TO_DATE(TO_CHAR(TO_DATE('&date1'),
new   1: SELECT MONTHS_BETWEEN(TO_DATE(TO_CHAR(TO_DATE(''),
Enter value for date2:
old   3:        TO_DATE(TO_CHAR(TO_DATE('&date2'), 'mmyyyy'),
new   3:        TO_DATE(TO_CHAR(TO_DATE(''), 'mmyyyy'),
 DIFF_DATE
----------
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SQL>