What is Atlantic Standard Time Zone?
[[Image:timezoneswest.PNG|thumb|right|250px|AST is [[UTC-4]].]] The '''Atlantic Standard Time Zone (AST)''' is a geographic region that keeps [[time]] by subtracting four hours from Greenwich Mean Time ([[GMT]]), resulting in GMT-4 ([[UTC-4]]). The clock time in this zone is based on the [[mean solar time]] of the 60th degree [[Meridian (geography)|meridian]] west of the [[Greenwich Observatory]]. The [[Canada|Canadian]] [[province]]s of [[New Brunswick]], [[Nova Scotia]] and [[Prince Edward Island]] keep time by subtracting four hours from UTC. So does [[Bermuda]], an island [[territory]] in the [[Atlantic Ocean|North Atlantic]]. In the summer, both places use [[daylight saving time]]. They keep ''Atlantic Daylight Time (ADT)'' (UTC-3) in the summer. Other parts of the world that keep time by subtracting four hours from UTC include: many [[Caribbean]] islands, including [[Puerto Rico]], the [[U.S. Virgin Islands]], and several [[South America]]n countries, such as [[Paraguay]], [[Chile]], [[Bolivia]], and parts of [[Brazil]]. [[Venezuela]] used AST until December 9, 2007, when it switched to [[UTC-4:30]], but switched back to AST on May 1, 2016, at 2:30 a.m. local time.<ref>{{Cite web|url=https://www.timeanddate.com/news/time/venezuela-change-timezone.html|title=Clocks to Go Forward Permanently in Venezuela|date=April 18, 2016|website=Time and Date|access-date=April 19, 2016}}</ref> ==References== {{reflist}} ==Other websites== * [http://www.travel.com.hk/region/timezone.htm World time zone map] {{Webarchive|url=https://web.archive.org/web/20151224150321/http://www.travel.com.hk/region/timezone.htm |date=2015-12-24 }} * [http://geography.about.com/library/misc/ntimezones.htm U.S. time zone map] {{Webarchive|url=https://web.archive.org/web/20090215175709/http://geography.about.com/library/misc/ntimezones.htm |date=2009-02-15 }} * [http://aa.usno.navy.mil/faq/docs/us_tzones.html History of U.S. time zones and UTC conversion] {{Webarchive|url=https://web.archive.org/web/20041012083750/http://aa.usno.navy.mil/f