The areas that don't use DST remains on standard time zone all year. The time zone names may be completely different, even though the UTC offset is the same.
There are also 25 military timezone which follow the rule of 1 hour per 15 degrees longitude. These are named according to the NATO phonetic alphabet: Alpha, Bravo, Charlie, etc.
Another point that can cause confusion is that some time zone's names in totally different places have exactly the same abbreviation. In most countries, the political decision to make adjustments regarding timezone or DST is made for practical reasons, like saving energy, facilitating trade with neighboring areas, or boost tourism.
It was codified when Congress passed the Standard Time Act of 1918, and the Interstate Commerce Commission was put in charge of the time zone boundaries. The 2007 law lengthened daylight saving time by four to five weeks.
Other states with both Eastern and Central timezone are Tennessee, Kentucky, Indiana and Michigan. Oregon and Idaho have both Mountain and Pacific timezone.
The word “pontiff” can be interchanged with pope, according to the Associated Press stylebook, which is used by a majority of media outlets. “Papacy” is used when referring to the office and jurisdiction of the pope, according to the Merriam-Webster Dictionary.
The clock maintained on a church steeple, city hall or by a jeweler, in a window or outside pedestal. The practical concept of time meridians (timezone) was first credited to Dr. William Hyde Williston in the late 1700s.
The expansion of the railroads pushing to the Pacific Ocean was the largest motivation for a universal time standard and timezone. To maintain a fairly accurate railroad schedule, a time standard was absolutely necessary.
There were also major safety issues as many trains would share a single track and thus exact time was critical. A number of notable train crashes could have been averted if a better time system was adopted on a nationwide basis.
In 1966 the Department of Transportation was formed and took over the function of timezone setting and modifications in the US. It is hard to comprehend the world not on a universal time standard today.
By having an exact time standard humans added a very real and meaningful layer of stress to our lives that still impacts all of us today. The lack of an exact time standard allowed for far more flexibility in just about every aspect of everyone's life.
A vast majority of people were perfectly comfortable dividing the day in 3 or 4 parts. The four timezone in the US are: Eastern, Central, Rocky Mountain, and Pacific.
Also, a great way to find out what time it is around the country is look for a global clock it shows you all the timezone from different countries. However, these clocks were not sufficiently accurate to be used at sea to determine longitude and for scientific time measurement in the 18th century.
Chronometers measured time accurately in spite of motion or varying conditions, and became popular instruments among many merchant mariners during the 19th century. Time calculation became a serious problem for people traveling by train (sometimes hundreds of miles in a day), according to the Library of Congress.
Operators of the new railroad lines needed a new time plan that would offer a uniform train schedule for departures and arrivals. Britain, which already adopted its own standard time system for England, Scotland, and Wales, helped gather international consensus for global timezone in 1884.
Sir Sandford Fleming was one of the key players in developing a satisfactory worldwide system of keeping time. He advocated the adoption of a standard or mean time and hourly variations from that following established timezone.
The International Meridian Conference in Washington DC, USA, adopted a proposal in October 1884. The proposal stated that the prime meridian for longitude and timekeeping should be one that passes through the center of the transit instrument at the Greenwich Observatory in the United Kingdom (UK).
The international 24-hour time -zone system grew from this, in which all zones referred back to GMT on the prime meridian. Interestingly, many French maps showed zero degrees in Paris for many years despite the International Meridian Conference’s outcomes in 1884.
Some countries such as China use a single time zone even though their territory extends beyond the 15 degrees of longitude. The expansion of transport and communication during the 19th century created a need for a unified time -keeping system, and timezone were introduced.
1913 time zone map of the United States, showing boundaries different from todayBefore the adoption of four standard time zones for the continental United States, many towns and cities set their clocks to noon when the sun passed their local meridian, overcorrected for the equation of time on the date of observation, to form local mean solar time. The use of local solar time became increasingly awkward as railways and telecommunications improved.
American railroads maintained many timezone during the late 1800s. Time calculation became a serious problem for people traveling by train (sometimes hundreds of miles in a day), according to the Library of Congress.
Train drivers must recalculate their own clock in order to know departure time. Operators of the new railroad lines needed a new time plan that would offer a uniform train schedule for departures and arrivals.
Four standard timezone for the continental United States were introduced at noon on November 18, 1883, in Chicago, IL, when the telegraph lines transmitted time signals to all major cities. In October 1884, the International Meridian Conference at Washington, D.C. adopted a proposal which stated that the prime meridian for longitude and timekeeping should be one that passes through the center of the transit instrument at the Greenwich Observatory in the United Kingdom.
The U.S. time -zone system grew from this, in which all zones referred back to GMT on the prime meridian. In 1960, the International Radio Consultative Committee formalized the concept of Coordinated Universal Time (UTC), which became the new international civil time standard.
Standard timezone in the United States and other regions are currently defined at the federal level by law 15 USC §260. It is ultimately the authority of the secretary of transportation, in coordination with the states, to determine which regions will observe which of the standard timezone and if they will observe daylight saving time.
As of August 9, 2007, the standard timezone are defined in terms of hourly offsets from UTC. Prior to this they were based upon the mean solar time at several meridians 15° apart west of Greenwich (GMT).
Only the full- time zone names listed below are official; abbreviations are by common use conventions, and duplicated elsewhere in the world for different timezone. The United States and its surrounding areas use nine standard timezone.
Time ZoneDSTStandard Atlantic (not observed) UTC04:00Puerto Rico, U.S. Virgin IslandsEasternUTC04:00UTC05:00Connecticut, Delaware, District of Columbia, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia, West Virginia ; Partially: Florida, Indiana, Kentucky, Michigan, Tennessee ; No DST observed, not defined by 15 U.S.C. §260: Natasha Island, Banjo Nero Bank, Serranilla BankCentralUTC05:00UTC06:00Alabama, Arkansas, Illinois, Iowa, Louisiana, Minnesota, Mississippi, Missouri, Oklahoma, Wisconsin ; Partially: Florida, Indiana, Kansas, Kentucky, Michigan, Nebraska, North Dakota, South Dakota, Tennessee, TexasMountainUTC06:00UTC07:00Arizona (no DST outside of Navajo Nation) , Colorado, Montana, New Mexico, Utah, Wyoming ; Partially: Idaho, Kansas, Nebraska, North Dakota, Oregon, South Dakota, TexasPacificUTC07:00UTC08:00California, Nevada, Washington (state) ; Partially: Idaho, OregonAlaskaUTC08:00UTC09:00 Partially: AlaskaHawaiiAleutianUTC09:00UTC10:00Hawaii (no DST observed in Hawaii); Partially: Alaska ; No DST observed, not defined by 15 U.S.C.
In practice, military crews may simply use Zulu time (UTC±00:00) when on these islands. Because they exist on opposite sides of the International Date Line, it can, for example, be noon Thursday on Baker and Howland islands while simultaneously being noon Friday on Wake Island.
Roughly follows the border between Wisconsin (to the south and west) and the Upper Peninsula (U.P.) Observe eastern time follows Lake Michigan divides a small portion of Northwestern Indiana near Chicago from the rest of the state follows the border between Illinois (west) and Indiana (east) divides a small portion of Southwestern Indiana from the rest of the state divides Kentucky in half roughly along a line that is west of Louisville, Kentucky running from northwest to southeast.
Follows the border between northern Idaho (to the west) and northwestern Montana (to the east) turns west at 45°33.46N 114°33.89W / 45.55767°N 114.56483°W / 45.55767; -114.56483 (just south of New Peace Pass), and follows the Idaho County line to the Salmon River follows the Salmon River west to the town of Higgins, where the Salmon River turns north. This puts almost all of northern Idaho in the Pacific time zone, except for the small loop described next.
This loop to the north creates a curious situation where one can enter a more westerly time zone by traveling east over one of the bridges across this portion of the Salmon River. Turns south and follows the Snake River between Oregon (west) and Idaho (east) to the northern border of Mahler County, Oregon turns west and follows the northern border of Mahler County, Oregon to its western border, where it turns south follows the western border of Mahler County to latitude 42.45° (42°27 N), where it turns east, and returns to the Oregon/Idaho border turns south and follows the border between Oregon (west) and Idaho (east) turns east and follows the border between Idaho (north) and Nevada (south) along the 42nd parallel north to longitude 114.041726 W. turns south and follows the border between Nevada (west) and Utah (east), except for following the west city limit line of West Wend over dividing it from the rest of Nevada, and putting it in the mountain time zone.
However: The Navajo Nation observes DST throughout its entire territory, including the portion that lies in Arizona. Also, some Indiana counties near Cincinnati and Louisville were on eastern time (ET), but did (unofficially) observe DST.