Map of time zones in usa

You are free to use our US time zone map for educational and commercial uses. Attribution is required.

I was stranded there for two days and was in awe at the accuaracy of your site. I retrived your site now to plan communications with contacts in Japan. I Thank You! Gary C. Fort Myers , Florida I am a travel specialist of Expedia and I always pull this site up for time references.

Map of time zones in usa

A time zone is an area which observes a uniform standard time for legal , commercial and social purposes. Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude , because it is convenient for areas in frequent communication to keep the same time. Time zones are defined as one or two offsets from Coordinated Universal Time UTC , and if two offsets are used the days when the offset changes. Some time zones switch between offsets throughout the year due to daylight saving time DST. Areas of extreme latitude are more likely to use DST. DST is usually used for about half of the year, typically by adding one hour to local time during spring and summer. When DST is in effect, approximately during spring and summer, their UTC offset is increased by one hour except for Lord Howe Island , where it is increased by 30 minutes. The apparent position of the Sun in the sky, and thus solar time , varies by location due to the spherical shape of the Earth. This variation corresponds to four minutes of time for every degree of longitude , so for example when it is solar noon in London , it is about 10 minutes before solar noon in Bristol , which is about 2. The Royal Observatory, Greenwich , founded in , established Greenwich Mean Time GMT , the mean solar time at that location, as an aid to mariners to determine longitude at sea, providing a standard reference time while each location in England kept a different time. In the 19th century, as transportation and telecommunications improved, it became increasingly inconvenient for each location to observe its own solar time. Around August 23, , time signals were first transmitted by telegraph from the Royal Observatory. Some British clocks from this period have two minute hands, one for the local time and one for GMT. On November 2, , the then British Colony of New Zealand officially adopted a standard time to be observed throughout the colony.

Many applied the time at a local astronomical observatory to an entire country, without any reference to GMT. I am a travel specialist of Expedia and I always pull this site up for time references.

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There are 9 time zones by law in the USA and its dependencies. However, adding the time zones of 2 uninhabited US territories, Howland Island and Baker Island , brings the total count to 11 time zones. The contiguous US has 4 standard time zones. In addition, Alaska , Hawaii , and 5 US dependencies all have their own time zones. Since Howland Island and Baker Island constitute the world's westernmost landmasses in relation to the International Date Line , making them the last places on Earth where any date exists, they are sometimes assigned a theoretical 12th time zone called Anywhere on Earth AoE. The time zones in the contiguous US are often referred to by their generic name, without making a difference between standard time and Daylight Saving Time designations. In practice, this means that the local time in these time zones changes when DST begins and ends. Note: Local time in these time zones changes when Daylight Saving Time begins and ends.

Map of time zones in usa

Pacific time. Fri Mar Mountain time. Central time. Eastern time.

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All rights reserved. Archived from the original PDF on May 14, Your email address will not be published. Bobby E. Internally, operating systems typically use UTC as their basic time-keeping standard , while providing services for converting local times to and from UTC, and also the ability to automatically change local time conversions at the start and end of daylight saving time in the various time zones. Davao City , Philippines. Archived from the original on November 30, Saturday, November 21, ". Archived from the original on December 28, Archived from the original on February 14, All nations currently use standard time zones for secular purposes, but not all of them apply the concept as originally conceived. Archived PDF from the original on September 4, More internationally oriented websites may show times in UTC only or using an arbitrary time zone. Archived from the original on October 28, Download as PDF Printable version.

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A time zone is an area which observes a uniform standard time for legal , commercial and social purposes. On November 2, , the then British Colony of New Zealand officially adopted a standard time to be observed throughout the colony. Geology Geological time age chron eon epoch era period Geochronology Geological history of Earth. American Practical Navigator. This typically involves advancing clocks by an hour near the start of spring and adjusting back in autumn "spring forward", "fall back". Baker Island Howland Island. In Google Calendar , calendar events are stored in UTC although shown in local time and might be changed by a time-zone changes, [46] although normal daylight saving start and end are compensated for similar to much other calendar software. He proposed 24 hourly time zones, which he called "longitudinal days", the first centred on the meridian of Rome. Read View source View history. The apparent position of the Sun in the sky, and thus solar time , varies by location due to the spherical shape of the Earth.