Honolulu, and the entire state of Hawaii, observes Hawaii-Aleutian Standard Time (HAST), which is UTC-10 (10 hours behind Coordinated Universal Time). Hawaii does not observe Daylight Saving Time, so the offset remains constant year-round.
This makes Hawaii the earliest time zone in the United States. For example, when it is 12:00 PM (noon) in New York (EDT, UTC-4), it is 6:00 AM in Honolulu.