Midway Atoll ( /ˈmɪdweɪ/; also called Midway Island and Midway Islands; Hawaiian: Pihemanu Kauihelani) is a 2.4-square-mile (6.2 km²) atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 (also known as Samoa Time), eleven hours behind Coordinated Universal Time and one hour behind the state of Hawaiʻi. Midway Atoll is an unorganized, unincorporated territory of the United States, and the former home of the Midway Naval Air Station (former ICAO PMDY). It is less than 140 nautical miles (259 km; 161 mi) east of the International Date Line, about 2,800 nautical miles (5,200 km; 3,200 mi) west of San Francisco, and 2,200 nautical miles (4,100 km; 2,500 mi) east of Tokyo. It consists of a ring-shaped barrier reef and several sand islets. The two significant pieces of land, Sand Island and Eastern Island, are habitat for millions of seabirds. The island sizes are shown here: