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What Time Is It?
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Current
Time in UTC/GMT
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A Clock
The GMT clock above requires Java to be enabled. The clock in the browser status line at the bottom of the window requires your browser's JavaScript functionality to be enabled.
The clock accuracy depends upon the accuracy of the clock setting of your PC; we have have (Windows) software links, below, to automatically update your PC clock.
Preface
What time is it? An easy question, right? The first impulse is to look at the clock on the wall or the wristwatch. The answer is a little more complicated when you cross continents and time zones and deal with winter and summer or standard and daylight savings time.
The Explanation
So how do we tell time around the world?
Shortwave broadcasters and radio amateurs use a universal time standard known as UTC (Universal Time Coordinated) or GMT (Greenwich Mean Time). UTC is the term currently in favor, but you will find broadcasters and publications using "Coordinated Universal Time", "Universal Time" (UT), "Greenwich Mean Time" (GMT) and "world time". Military personnel use the term "Zulu" time. For our purposes, all terms mean the same thing.
Further, the 24-hour clock is used to avoid confusion with "a.m." and "p.m." Some of you may recognize the term "military time". The time is expressed as 4 digits (hours and minutes) without punctuation, and 12 hours are added to the hours after 1 p.m. For example, 9:24 a.m. is 0924 and 9:24 p.m. is 2124 (12+9=21).
UTC is based upon the time on the 0 degree longitude passing through Greenwich, England, home of the original Royal Greenwich Observatory. Richard B. Langley of the Department of Geodesy and Geomatics Engineering at the University of New Brunswick, Fredericton, has written a brief titled A Few Facts Concerning GMT, UT, and the RGO. It is recommended reading.
If you know the number of hours difference between your local time and UTC, then you can convert UTC time to your local time.
One way is to tune into the National Institute of Standards and Technology stations WWV (in Colorado) or WWVH (in Hawaii). These time-and-frequency standard stations broadcast on 2500, 5000, 10000, and 15000 kHz; WWV also broadcasts on 20000 kHz. Time, in "Coordinated Universal Time", is announced every minute. Calculate the difference between your local time and the time announced by WWV/WWVH.
There's one more thing to remember when you are converting time to or from UTC. If the difference in hours rolls over 0000 UTC, you must adjust the day as well. For example, in the USA 0100 UTC Sunday is 2000 Saturday Eastern Standard Time.
Setting the clock in Windows 
When installing a new copy of Windows XP/SP2, silly me, I read the help files when it came time to pick the time zone. I discovered a surprise. Whereas Windows XP has support for Network Time, it automatically updates the time only once a week. If the computer is not powered on and not connected to the Internet, the time correction attempt is skipped for another week, and another and... well, you get the idea. XP isn't clever enough to run the time check when you do sign on to the net. Windows XP does not have any configuration options to control the frequency of clock setting; updating the clock more frequently is a manual excercise by drilling down through the Control Panel. So what do you do?
One alternative is to run a third party application to set the computer clock. Over the years Tardis — www.kaska.demon.co.uk — remains one of the most stable programs in the shareware stable of software. There are caveats when using the HTTP protocol to set the computer clock — www.maths.tcd.ie/~dwmalone/time/tardis.html — and setting the update to very short intervals of time. The results of a search using "set computer clock atomic XP" will show a variety of solutions, but we like the relatively simple solution of modifying the registry. The instructions are within the page at www.worldtimeserver.com/atomic-clock. There is a danger in using RegEdit, and you can bollix the computer. If you are not comfortable editing the registry, don't do this. But the advantages of this solution are significant: there is no extra program to run at startup, and resources are conserved. In any case, neither I or TRS Consultants can be held responsible if you break something.
Links
Computer synchronization software (Windows) to set your PC or Mac clock accurately. Grayline maps make twilight DXing come alive.
