Hong Kong (HKT, UTC+8) is 1 hour ahead of Gold Coast, Queensland (AEST, UTC+10) during standard time. However, Queensland does not observe daylight saving time, while Hong Kong never does. So the difference remains constant year-round.
There are other places named Gold Coast (e.g., in Ghana, Chicago, Florida), but the most common international reference is the Queensland, Australia coastal city. Always confirm which Gold Coast is meant.