A report on Time zone

Time zones of the world
Time zones of the world
Plaque commemorating the Railway General Time Convention of 1883 in North America
The control panel of the Time Zone Clock in front of Coventry Transport Museum
1913 time zone map of the United States, showing boundaries very different from today
World map of time zones in 1928
Difference between sun time and clock time during daylight saving time:

Area that observes a uniform standard time for legal, commercial and social purposes.

- Time zone
Time zones of the world

40 related topics with Alpha

Overall

World map of current time zones

Coordinated Universal Time

6 links

Primary time standard by which the world regulates clocks and time.

Primary time standard by which the world regulates clocks and time.

World map of current time zones
Graph showing the difference DUT1 between UT1 and UTC (in seconds). Vertical segments correspond to leap seconds.

Time zones around the world are expressed using positive or negative offsets from UTC, as in the list of time zones by UTC offset.

Worldwide time zones at present

Standard time

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Synchronisation of clocks within a geographical region to a single time standard, rather than a local mean time standard.

Synchronisation of clocks within a geographical region to a single time standard, rather than a local mean time standard.

Worldwide time zones at present
Telegraphic equipment used to transmit standard time from the Allegheny Observatory

Applied globally in the 20th century, the geographical regions became time zones.

An ancient water clock that lets hour lengths vary with season.

Daylight saving time

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Practice of advancing clocks (typically by one hour) during warmer months so that darkness falls at a later clock time.

Practice of advancing clocks (typically by one hour) during warmer months so that darkness falls at a later clock time.

An ancient water clock that lets hour lengths vary with season.
George Hudson invented modern DST, proposing it first in 1895.
DST was first implemented in the United States to conserve energy during World War I. (poster by United Cigar Stores)
Retailers generally favor DST; United Cigar Stores hailed a 1918 DST bill.
William Willett independently proposed DST in 1907 and advocated it tirelessly.
A 2001 US public service advertisement reminded people to adjust clocks.
The William Willett Memorial Sundial in Petts Wood, south London, is always on DST.
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Northern hemisphere summer
Southern hemisphere summer
Formerly used daylight saving
Never used daylight saving

The effect also varies according to how far east or west the location is within its time zone, with locations farther east inside the time zone benefiting more from DST than locations farther west in the same time zone.

Greenwich clock with standard measurements

Greenwich Mean Time

5 links

Mean solar time at the Royal Observatory in Greenwich, London, counted from midnight.

Mean solar time at the Royal Observatory in Greenwich, London, counted from midnight.

Greenwich clock with standard measurements
Clock in Kumasi, Ghana, set to GMT.

The term 'GMT' is also used as one of the names for the time zone UTC+00:00 and, in UK law, is the basis for civil time in the United Kingdom.

World map of current time zones

UTC offset

4 links

Difference in hours and minutes between Coordinated Universal Time and local solar time, at a particular place.

Difference in hours and minutes between Coordinated Universal Time and local solar time, at a particular place.

World map of current time zones

A time zone is a geographical region in which residents observe the same standard time.

Clock on The Exchange, Bristol, showing two minute hands, one for London time (GMT) and one for Bristol time (GMT +11 minutes).

Railway time

2 links

The standardised time arrangement first applied by the Great Western Railway in England in November 1840, the first recorded occasion when different local mean times were synchronised and a single standard time applied.

The standardised time arrangement first applied by the Great Western Railway in England in November 1840, the first recorded occasion when different local mean times were synchronised and a single standard time applied.

Clock on The Exchange, Bristol, showing two minute hands, one for London time (GMT) and one for Bristol time (GMT +11 minutes).

Despite this early reluctance, railway time rapidly became adopted as the default time across the whole of Great Britain, although it took until 1880 for the government to legislate on the establishment of a single standard time and a single time zone for the country.

The monument 'The 15th Meridian' in Stargard, Poland

Central European Time

3 links

Standard time which is 1 hour ahead of Coordinated Universal Time (UTC).

Standard time which is 1 hour ahead of Coordinated Universal Time (UTC).

The monument 'The 15th Meridian' in Stargard, Poland
European winter
European summer
Map of Petsamo area in northern Finland/Soviet Union/Russia. The green area is the Finnish part of the Rybachi peninsula (Kalastajasaarento) which was ceded to the Soviet Union after the Winter War. The Red area is the Jäniskoski-Niskakoski area ceded to the USSR in 1947.

The 15th meridian east is the central axis for UTC+01:00 in the world system of time zones.

UTC−12:00: blue (December), orange (June), yellow (year-round), light blue (sea areas)

UTC−12:00

1 links

Identifier for a time offset from UTC of −12:00.

Identifier for a time offset from UTC of −12:00.

UTC−12:00: blue (December), orange (June), yellow (year-round), light blue (sea areas)

UTC−12:00 is a nautical time zone comprising the high seas between 180° and 172°30′W longitude, and the time is obtained by subtracting twelve hours from UTC.

A graticule on the Earth as a sphere or an ellipsoid. The lines from pole to pole are lines of constant longitude, or meridians. The circles parallel to the Equator are circles of constant latitude, or parallels. The graticule shows the latitude and longitude of points on the surface. In this example, meridians are spaced at 6° intervals and parallels at 4° intervals.

Longitude

1 links

Geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body.

Geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body.

A graticule on the Earth as a sphere or an ellipsoid. The lines from pole to pole are lines of constant longitude, or meridians. The circles parallel to the Equator are circles of constant latitude, or parallels. The graticule shows the latitude and longitude of points on the surface. In this example, meridians are spaced at 6° intervals and parallels at 4° intervals.

Because of the Earth's rotation, there is a close connection between longitude and time measurement.

The equation of time — above the axis a sundial will appear fast relative to a clock showing local mean time, and below the axis a sundial will appear slow.

Local mean time

2 links

Form of solar time that corrects the variations of local apparent time, forming a uniform time scale at a specific longitude.

Form of solar time that corrects the variations of local apparent time, forming a uniform time scale at a specific longitude.

The equation of time — above the axis a sundial will appear fast relative to a clock showing local mean time, and below the axis a sundial will appear slow.

This measurement of time was used for everyday use during the 19th century before time zones were introduced beginning in the late 19th century; it still has some uses in astronomy and navigation.