Hawaii celebrates Kamehameha Day with events, parades - Hawaii News Now - KGMB and KHNL. Hawaii celebrates Kamehameha Day with events, parades. Thursday, June 11 marks Kamehameha Day, an annual state holiday celebrating the king who united the Hawaiian islands. Several events are taking place across the state to honor King Kamehameha the Great. Time: 8:30 a.m.