Philippine Standard Time Philippine Standard Time Philippine Standard Time (, abbreviated PST or PhST), also known as Philippine Time (PHT), is the official name for the time in the Philippines. The country only uses one time zone (), and for a short period, it also used daylight saving time. Geographically, the Philippines lies within 116°40′ and 126°34′ east of the Prime Meridian, and is physically located within the time zone. Philippine Standard Time is maintained by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA). The Philippines shares the same time zone with Hong Kong, Macau, Singapore, China, Taiwan, Malaysia, Brunei, central Indonesia,
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