Utc Gmt 0


April 26, 2012, 2:48am. I Have just learnt after years of confusion that the main difference between the two terms ( apart From the 9 sec. ) relates to the fact that UTC cannot change in sync with GMT at the changeover point for GMT to enter Daylight Saving Time therefore a one hour difference appears at that point in time for a period of 7 months.

How To Convert To Utc Time

Coordinated Universal Time (UTC) is used as the official world reference for time. Coordinated Universal Time replaced the use of Greenwich Mean Time (GMT) in 1972. You will often see time zones represented similar to UTC - 5h or GMT - 5h. In this example the (-5h) refers to that time zone being five hours behind UTC or GMT and so forth for the other time zones. UTC+5h or GMT +5h would refer to that time zone being five hours ahead of UTC of GMT and so forth for the other time zones.
The usage of UTC and GMT is based upon a twenty four hour clock, similar to military time, and is based upon the 0 degrees longitude meridian, referred to as the Greenwich meridian in Greenwich, England.
Coordinated Universal Time is based on cesium-beam atomic clocks, with leap seconds added to match earth-motion time, where as Greenwich Mean Time is based upon the Earth's rotation and celestial measurements. Coordinated Universal Time is also known Zulu Time or Z time.
In areas of the United States that observe Daylight Saving Time local residents will move their clocks ahead one hour when Daylight Saving Time begins. As a result, their UTC or GMT offset would change from UTC -5h or GMT - 5h to UTC -4h or GMT - 4h. In places not observing Daylight Saving Time the local UTC or GMT offset will remain the same year round. Arizona, Puerto Rico, Hawaii, U.S. Virgin Islands and American Samoa do not observe Daylight Saving Time.
In the United States Daylight Saving Time begins at 2:00 a.m. local time on the second Sunday in March. On the first Sunday in November areas on Daylight Saving Time return to Standard Time at 2:00 a.m. The names in each time zone change along with Daylight Saving Time. Eastern Standard Time (EST) becomes Eastern Daylight Time (EDT), and so forth. A new federal law took effect in March 2007 which extends Daylight Saving Time by four weeks.
The United States uses nine standard time zones. From east to west they are Atlantic Standard Time (AST), Eastern Standard Time (EST), Central Standard Time (CST), Mountain Standard Time (MST), Pacific Standard Time (PST), Alaskan Standard Time (AKST), Hawaii-Aleutian Standard Time (HST), Samoa standard time (UTC-11) and Chamorro Standard Time (UTC+10). View the standard time zone boundaries.

Coordinated Universal Time (UTC)Greenwich Mean Time (GMT)
11:29 AM
11:29 AM

  • 2.1 GMT:Greenwich Mean Time 格林威治标准时间; 英国伦敦格林威治定为0°经线开始的地方,地球每15°经度 被分为一个时区,共分为24个时区,相邻时区相差一小时;例: 中国北京位于东八区,GMT时间比北京时间慢8小时。.
  • Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time at 0° longitude, and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT).

United States GMT/UTC Offsets

Time Zone in United StatesExamples of places in the United States using these Time ZonesUTC Offset
Standard Time
UTC Offset
Daylight Saving Time
AtlanticPuerto Rico, US Virgin IslandsUTC - 4hN/A
EasternConnecticut, Delaware, Florida, Georgia, part of Indiana, part of Kentucky, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, part of Tennessee, Vermont, Virginia, West Virginia and Washington, D.C.UTC - 5hUTC - 4h
CentralAlabama, Arkansas, Florida, Illinois, part of Indiana, Iowa, part of Kansas, part of Kentucky, Louisiana, part of Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Dakota, Oklahoma, part of South Dakota, part of Tennessee, most of Texas, and WisconsinUTC - 6hUTC - 5h
MountainArizona*, Colorado, part of Idaho, part of Kansas, Montana, part of Nebraska, New Mexico, part of North Dakota, part of Oregon, part of South Dakota, part of Texas, Utah, and WyomingUTC - 7hUTC - 6h
* n/a for Arizona except in the Navajo Nation which does observe daylight saving time.
PacificCalifornia, part of Idaho, Nevada, most of Oregon, WashingtonUTC - 8hUTC - 7h
AlaskaAlaska and a portion of the Aleutian Islands that is east of 169 degrees 30 minutes west longitude observes the Alaska Time Zone.UTC - 9hUTC - 8h
Hawaii - Aleutian
Unofficially often referred to as Hawaii Time Zone
Hawaii and a portion of the Aleutian Islands that is west of 169 degrees 30 minutes west longitude observes the Hawaii-Aleutian Standard Time Zone. Although Hawaii does not observe daylight saving time the Aleutian Islands do observe daylight saving time.UTC - 10hUTC - 9h
Hawaii does not observe daylight saving time. A portion of the Aleutian Islands which observes the Hawaii - Aleutian time zone does observe daylight saving time.
Time Zone Look Up by State with Current Local Times

All dates are shown in the format: month/day/year
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The Date.UTC() method accepts parameters similar to the Date constructor, but treats them as UTC. It returns the number of milliseconds since January 1, 1970, 00:00:00 UTC.


A full year.
An integer between 0 (January) and 11 (December) representing the month. Since ECMAScript 2017 it defaults to 0 if omitted. (Up until ECMAScript 2016, month was a required parameter. As of ES2017, it no longer is.)
An integer between 1 and 31 representing the day of the month. If omitted, defaults to 1.
An integer between 0 and 23 representing the hours. If omitted, defaults to 0.
An integer between 0 and 59 representing the minutes. If omitted, defaults to 0.
An integer between 0 and 59 representing the seconds. If omitted, defaults to 0.
An integer between 0 and 999 representing the milliseconds. If omitted, defaults to 0.
Utc gmt -5

Return value

A number representing the number of milliseconds for the given date since January 1, 1970, 00:00:00, UTC.


UTC() takes comma-delimited date and time parameters and returns the number of milliseconds between January 1, 1970, 00:00:00, universal time and the specified date and time.

Years between 0 and 99 are converted to a year in the 20th century (1900 + year). For example, 95 is converted to the year 1995.

The UTC() method differs from the Date constructor in two ways:

  1. Date.UTC() uses universal time instead of the local time.
  2. Date.UTC() returns a time value as a number instead of creating a Date object.

If a parameter is outside of the expected range, the UTC() method updates the other parameters to accommodate the value. For example, if 15 is used for month, the year will be incremented by 1 (year + 1) and 3 will be used for the month.

UTC() is a static method of Date, so it's called as Date.UTC() rather than as a method of a Date instance.


Using Date.UTC()

The following statement creates a Date object with the arguments treated as UTC instead of local: Firefox mac os x 10.5 8 download.


ECMAScript Language Specification (ECMAScript)

Browser compatibility

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Utc To Gmt 07

Compatibility notes

Date.UTC() with fewer than two arguments

When providing less than two arguments to Date.UTC(), ECMAScript 2017 requires that NaN is returned. Engines that weren't supporting this behavior have been updated (see bug 1050755, ecma-262 #642).

Utc Gmt Difference

See also