The Atlantic Time Zone also known by its commonly used abbreviation AST is a geological region that maintains a standard time by subtracting four hours from the primary time standard by which the world regulates clocks and time known as the Coordinated Universal Time, of UTC giving rise to UTC-4.
The clock time within the Atlantic Time Zone is primarily based on the calculation of the passage of time relative to the Sun”s position in the sky. This is known to astrologers and scientists as the mean solar time existing along the line of longitude generally referred to as the meridian 60° west of the Greenwich Observatory in London.
Atlantic Daylight Saving Time
The Atlantic Standard Time Zone during a specified number of months each year observes the practice of daylight saving time often referred to as summer time which includes the advancing of clocks during the summer months that are known to have more sunlight.
This Act was initiated to allow people to get up much earlier in the morning to take advantage of more daylight time during the evening hours. Throughout this period of daylight savings, countries which fall under the Atlantic Time Zone calculated a standard time by adjusting the clocks by 3 hours backward resulting on UTC-3.
In 1916 four canadian cities by local mandate adopted daylight saving time. The first of which was Brandon, Manitoba on the 17th of April also recognizes as the first city in the world to use it. The capital and largest city of the province of Manitoba known as Winnipeg became the second on April 23, followed by Halifax on April 30 accompanied by the port city of Hamilton Ontario on the 4th of June.
Atlantic Time Zones in Canada
Canada makes use of six central time zones based on the ideas put forward by Sir Sandford Flemming the Scottish Canadian Railway Engineer who played a critical role in developing of the world’s first time zone system. These time zones which range from the west to the east and include; the Pacific Time Zone, the Mountain Time Zone, the Central Time Zone, the Eastern Time Zone, the Atlantic Time Zone and the Newfoundland Time Zone.
Most Canadian provinces are acknowledged to observe daylight savings time or summer time at local time 2:00 a.m. on the second Sunday of the month of March by turning their clocks ahead one hour and returning to Standard Time on the first Sunday of the month of November at 2:00 a.m.
The territories of Brunswick, and Nova Scotia compute time specifically to compensate 4 hours from Greenwich Mean time or GMT-4. The Maritime province of Prince Edward Island as well as minor territories of the Canadian province of Quebec including the eastern Côte-Nord and the Magdalen Islands also recognize the Atlantic Standard Time Zone.
In spite of the fact that the entire section of the easternmost province of Canada known as Newfoundland and Labrador formally observes a Newfoundland Time Zone by subtracting 3 1/2 hours from Coordinated Universal Time UTC-03:30; it is a customary practice of most of the Labrador province to adopt a standard time based on the Atlantic Time Zone.
This exception is attributed to the legislation signed in 2011during which the province of Newfoundland and Labrador declared an amendment to the Standard Time Act of 1918 also known as the Calder Act. This amendment to the Act which became effective on November 6, 2011 allowed the province of Newfoundland and Labrador to observe daylight savings at the same time with the rest of Canada beginning and ending daylight saving time one minute after midnight local time.
Prior to today, daylight savings time observed in Canada began on the first Sunday in the month of April and ended in the month of October. However in keeping with to the new legislation passed in 2006, daylight savings time was amended to start three weeks earlier marking its beginning the second Sunday in March and continuing through to the first Sunday in November.
Territories falling under the Atlantic Time Zone and observing daylight saving time will experience a change in the name of the time zone from Eastern Standard Time (EST) to become Eastern Daylight Time (EDT). Some Canadian territories known for not adopting daylight saving time include Charlie Lake, Creston in the East Kootenays, Fort St. John, Taylor and Dawson Creek in British Columbia, as well as almost all of Saskatchewan with the exception of Delaware Beach and Creighton.
Most of the Canadian province of Saskatchewan throughout the year observed Central Standard time, however the city of Lloydminister bearing an unusual graphical distinction uses Mountain Standard Time as well as acknowledging daylight saving time as an exception. Under the Canadian Constitutional, laws associated with timekeeping are strictly a provincial matter which has subsequently led to a number of Canadian communities which have opt not to observe the official time zones.
Canadian Time Zones 101
There are no territories of the continental United States which officially fall within the Atlantic Time Zone; however both the U.S. Virgin Islands and Puerto Rico are seen as adopting the use of Atlantic Standard Time and as such are considered as territories governed by the Atlantic Time zone.
Although most territories including Canada, New Brunswick, Nova Scotia, east tip of Quebec, newfoundland and Labrador, Prince Edward Island, Thule, Greenland and Bermuda are considered falling under the Atlantic Time Zone participating in daylight standard time or Atlantic Daylight Time of ADT, by adding one hour to their clocks resulting in three hours behind Coordinated Universal Time UTC-3; other territories such as the U.S. Virgin Islands, Dominican Republic, Puerto Rico, Trinidad and Tobago, Barbados, Aruba and Curaçao UTC-4 does not utilize daylight saving time.
Time Zones & the International Date Line
Canada from the time of the late 1960’s has been closely and almost completely synchronized with daylight saving time observed in the United States in an effort to encourage a constant economic and social interconnectivity.