Japan Standard Time or JST (, Nihon Hyojunji, or Chuo Hyojunji) is the standard timezone in Japan, 9 hours ahead of UTC (i.e. it is UTC+09:00). There is no daylight saving time, though its introduction has been debated several times. During World War II, it was often called Tokyo Standard Time.

Is the following statement correct based on the text

does all of japan have the same time zone
yes