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Have you ever noticed that computers make the world's worst clocks? Sure, Windows is able to display the time in every conceivable format, and it switches between standard and daylight saving time without a hitch. But the time that appears on your taskbar probably runs fast or slow by at least a few minutes every week. As this is being written, my PC's clock is fast by 13 minutes, a state of affairs I have lived with for several months because it has fortuitously made me much more punctual.

Of course, you could simply reset your clock manually, but it will only drift noticeably out of whack again in a matter of days. Since e-mail and file time stamps are generated by your computer's clock, keeping your PC on the right time is more important than you might assume. Why not harness the Internet to control your PC clock's accuracy?

The National Institute of Standards and Technology in Boulder, Colorado, maintains an atomic clock that you can query over the Internet for the official U.S. time. At Public NTP Time Servers, you'll see a complete list of Internet time servers. Follow these steps to set up Internet time synchronization in various versions of Windows.

Windows XP (Home Edition or Professional): The task is a major cinch--simply right-click the time display on the taskbar, choose Adjust Date/Time, click the Internet Time tab, and check Automatically synchronize with an Internet time server. Choose one of the servers on the drop-down list (NIST's server can be found at time.nist.gov), click Update Now, and finally click OK. Windows XP will try to synchronize with the time server automatically once a week. If your Internet connection is intermittent, XP will try to sync at regular intervals until it succeeds.

Windows 2000: Earlier versions of Windows lack XP's easy time-synchronization interface, but they include the underlying Internet time commands that make synchronization work--if you're comfortable using the command line. If you're command-line averse, you may want to give the YATS32 utility described below a try; it works fine with Windows 2000.

Choose Start, Programs, Accessories, Command prompt to open a command prompt window. Then enter net time /setsntp:address, where address is the domain name of the time server. For example, the command net time /setsntp:time.nist.gov sets NIST's clock as the default time server for the system. To set the time, use the command net time /set. To automate this process, simply use the command at 23:30 /every:Su "net time /set" (for example), which schedules synchronization to occur every Sunday at 11:30 p.m. You can also use this tip with Windows XP if you prefer to have complete control over where and when you synchronize your clock.

Windows 95/98/Me: All three of these operating systems lack the Internet time-synchronization tools of Windows 2000 and XP (although they do permit syncing with another computer on a local network via the Net time command). Fortunately, there are numerous downloadable utilities available to fill the gap. One is Dillobits Software's $19 YATS32, a 1.55MB shareware program. YATS32 offers more clock-synchronization options than you'll probably ever need (see FIGURE 1). Besides letting you control when and where you set your clock, YATS32 monitors your computer's clock and tells you just how far it drifts each day. Now if only it would tell you why.