Chatham Standard Time Zone Chatham Standard Time Zone The Chatham Standard Time Zone is a geographic region that keeps time by adding twelve hours and forty-five minutes to Coordinated Universal Time (UTC) resulting in . The Chatham Standard Time Zone is used exclusively in the Chatham Islands, New Zealand, located in the South Pacific Ocean at 43°53′54″S, 176°31′44″W. It is one of only three time zones with a 45-minute offset from UTC, the others being Nepal Time () and the unofficial Australian Central Western Time (). During summer daylight saving time is observed and clocks are advanced one hour. Chatham Daylight Time (CHADT) is
Aleutian subduction zone rocks, with trace amounts of Paleozoic rocks intruded by Mesozoic batholiths. Most of the Aleutian Islands are composed of sedimentary rocks from granitic and metamorphic rocks from Oligocene-Miocene. There are Quaternary volcanoes on the north of the Aleutian Islands structural axis, which is composed of andesite mostly, mixed with olivine basalt to rhyolite. The eastern Aleutian volcanoes have more silicic magma while the western Aleutian arcs lack the sial magma. The Aleutian Trench formation is associated with the subduction of the Pacific Plate beneath the North American plate. The horizontally-curved shape of the trench is due to the change in