64 lines
4.5 KiB
HTML
64 lines
4.5 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="security" content="public" />
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<meta name="Robots" content="index,follow" />
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<meta name="DC.Type" content="concept" />
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<meta name="DC.Title" content="Coordinated universal time" />
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<meta name="abstract" content="Coordinated universal time (UTC) is a time scale that is kept by time laboratories around the world and is determined by using highly precise atomic clocks. The UTC time is accurate to approximately a nanosecond (billionth of a second) per day. UTC is located at 0 degrees latitude, the Prime Meridian." />
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<meta name="description" content="Coordinated universal time (UTC) is a time scale that is kept by time laboratories around the world and is determined by using highly precise atomic clocks. The UTC time is accurate to approximately a nanosecond (billionth of a second) per day. UTC is located at 0 degrees latitude, the Prime Meridian." />
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<meta name="DC.Relation" scheme="URI" content="rzaticoncepts.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzatitime.htm" />
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<meta name="DC.Relation" scheme="URI" content="../rzakz/rzakzqtime.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Format" content="XHTML" />
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<meta name="DC.Identifier" content="rzatiutc" />
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<meta name="DC.Language" content="en-us" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>Coordinated universal time</title>
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</head>
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<body id="rzatiutc"><a name="rzatiutc"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Coordinated universal time</h1>
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<div><p>Coordinated universal time (UTC) is a time scale that is kept by
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time laboratories around the world and is determined by using highly precise
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atomic clocks. The UTC time is accurate to approximately a nanosecond (billionth
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of a second) per day. UTC is located at 0 degrees latitude, the Prime Meridian.</p>
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<p>UTC is used as the starting point to calculate the system
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time. To calculate the system time from UTC, the system's offset from UTC
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is added to UTC. The offset specifies the number of hours and minutes that
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the system is either west or east of UTC. Everything west of the Prime Meridian
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has a negative offset and everything east has a positive offset. Then, the
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offset is applied to UTC to calculate the system time. The system time is
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displayed in the time of day system value.</p>
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<p>The following figure shows where UTC is located relative to Server A. UTC
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has a time value of 4:00 p.m. Server A is located in the United States of
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America in the Central Standard Time zone. Server A is located west of UTC
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6 hours; therefore, Server A is offset from UTC by -06:00 hours. To calculate
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Server A's system time, add a negative 6 hours (-06:00) to 4:00 p.m., which
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is the current time value for UTC. With this calculation, Server A's local
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system time is 10:00 a.m.</p>
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<br /><img src="rzati503.gif" alt="Server A has a time value of 10:00 a.m. The current UTC time is 4:00 p.m." /><br /></div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzaticoncepts.htm" title="Use this information to understand time management concepts such as time zones, coordinated universal time (UTC), and daylight saving time (DST).">Concepts</a></div>
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</div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
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<div><a href="rzatitime.htm" title="Use this information to understand time concepts such as time zones, coordinated universal time, system time, and job time.">Time</a></div>
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</div>
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<div class="relref"><strong>Related reference</strong><br />
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<div><a href="../rzakz/rzakzqtime.htm">Time of day (QDATETIME) system value</a></div>
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</div>
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</div>
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</body>
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</html>
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