UTC−09:00 is a time offset that subtracts 9 hours from Coordinated Universal Time (UTC). This time is used in:
UTC+09:00 is an identifier for a time offset from UTC of +09.
During Japan occupations (of Borneo, Burma, Hong Kong, Dutch East Indies, Malaya, Philippines, Singapore, and French Indochina), it was used as a common time with Tokyo until the fall of Empire of Japan.