Fourteen time zones and two ocean-to-continent connections separate Oahu from Lower Saxony, which is precisely why routing strategy matters more on this journey than almost any other transatlantic-Pacific hybrid I cover. There is no nonstop option, so business class from Honolulu to Hannover always involves at least one stop, and the smart money routes through the mainland US on American or United, then across the Atlantic on a partner or codeshare into Frankfurt or Munich before the short rail or feeder hop to Hannover. Delta's preferred routing typically funnels through Seattle or Detroit before a transatlantic leg into Amsterdam or Paris. In practice, I've found United's Polaris business class, with its reverse-herringbone seating and direct aisle access on 777 and 787 aircraft out of San Francisco or Los Angeles, to be the most consistent product for the long Pacific-to-Europe haul, while American's Flagship Suite on select 777-300ERs offers similar privacy if your itinerary routes through Dallas or Chicago.
My own preference after years flying this exact combination is to build in a deliberate overnight in whichever US gateway city you're using, rather than a tight same-day connection — the HNL redeye already costs you a night's sleep, and a fresh transatlantic departure the next evening dramatically improves how you land in Germany. If Frankfurt is your entry point rather than a direct Hannover arrival, the airport's excellent long-distance train hall inside Terminal 1 makes the onward journey to Hannover Hauptbahnhof faster than waiting for a regional connecting flight.
Deal-wise, January through March and again in October and November consistently produce the softest fares on this Pacific-Atlantic combination, as both Hawaii leisure demand and German business travel dip simultaneously. Given the multi-carrier complexity and fare volatility of stitching together HNL-to-HAJ in business class, setting automated fare alerts across American, Delta, and United is the only realistic way to catch these windows before they close.
