Know exactly when to book the hard-to-get stuff.
Pick the day you want to visit. Hawaii Hacks calculates the published booking window — and, where the operator publishes a release time, converts it from Hawaiʻi time into your local time.
Your target dates
Diamond Head State Monument
Non-Hawaiʻi residents need advance reservations. Official reservations can be made up to 30 days before the visit.
Hanauma Bay
Admission-only reservations open two days before the visit at 7:00 a.m. Hawaiʻi Standard Time. Hanauma Bay is closed Mondays and Tuesdays. Admission-with-transport packages follow a separate month-ahead window; compare booking options.
USS Arizona Memorial
Reservations are released in two windows: 8 weeks ahead and again the preceding day, both at 3:00 p.m. Hawaiʻi Standard Time.
Rules are sourced from current official reservation pages and should still be rechecked before booking, especially after closures or operational changes.
Choose one or more visit dates to see the exact booking windows.
Official reservation links above are not affiliate links. Separate activity links may earn Hawaii Hacks a commission.
Published official booking rules
Last source review: 18 October 2026. Always use the official booking site for the actual reservation.
When do Oʻahu reservations open?
The calculator converts those rules into your chosen visit dates. For attractions with a stated release time, it also shows that moment in your local timezone.
Book fixed reservations first
Once those dates are locked, fit flexible tours and activities around them instead of building an itinerary first and discovering later that a key reservation is unavailable.