Is Microsoft's Time Warped?

Does anybody really know what time it is? Apparently Microsoft doesn't.

An Internet Time utility built into Windows XP Home and Professional editions that is supposed to ensure correct system time instead suffers from intermittent bouts of tardiness, PC World has learned. Microsoft intends the utility to synchronize your PC's internal clock via the Internet with the atomic clock maintained by the National Institute of Standards and Technology. The atomic clock is considered the Holy Grail of timekeeping. It is referenced daily by millions, from the military to stock market traders and researchers, by means other than Microsoft's Internet Time utility.

But repeated tests of the Windows XP Internet Time utility produced a variety of unharmonious results. Compared with the NIST's atomic clock, Microsoft was repeatedly off by as much as nine minutes.

A day after PC World questioned Microsoft about the time discrepancies, the company reports it has fixed the problem. Even so, it could take a week or longer for millions of Windows XP PCs to be set to the correct time. That's because the Windows XP Internet Time utility synchronizes your PC's clock automatically only once a week. If your PC isn't connected to the Internet at that time, the utility can't make the update.

To be fair, Microsoft figured it was correcting a common problem with PCs by building in the Internet Time utility because system clocks on PCs, especially notebooks, routinely get out of whack. Only Net-connected PCs running Windows XP can take advantage of the new utility.

Keeping your PC on correct system time is more important than you might assume. Accurate time is an important factor to ensure data files and e-mail get the correct time stamps. It is particularly important if you synchronize data files, because time stamps often determine which file is more recent. Incorrect time can also make e-mail look older (or newer) than it actually is, a trick used by many e-mail spammers who deliberately change their system time.

A computer server that wasn't syncing properly was at the root of the problem, says Bryan Starbuck, a Microsoft software developer. The company was previously unaware of the inconsistency. Now, the Internet Time utility appears to be working correctly.

Getting Win XP on Time

Microsoft is one of many companies and organizations that host what are known as "time servers" on the Internet. Each of these servers mirrors the time (to the second) that NIST hosts on its servers.

Now that Microsoft has corrected its time server, the time-sensitive can manually update a PC or modify the utility's settings to force Windows XP to check the alternate NIST server for the correct time. Note that Windows XP does not provide the utilities to PCs on a network domain; such PCs often have login scripts that synchronize the PCs' time with the network server's clock.

Under the default setting, Microsoft lists its own time.windows.com server. However, you can direct Windows XP to sync directly with the NIST server, or another online authority. A list of available servers is on the Network Time Protocol home page.

To adjust the utility in any version of Windows XP, 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.

If you want to sync directly with NIST, choose the alternate server time.nist.gov from a drop-down list. Then click Update Now, and Windows will synchronize your PC's clock. Or you can enter one of the other available servers.

If left unattended, Windows XP will synchronize with the time server automatically on a weekly basis.

Find Your PC's Lost Time

Microsoft's time synchronization feature is meant to correct a PC's nasty habit of losing time. Computers can lose as much as one minute each hour with some PC configurations, say developers of time-setting utilities. With each PC reboot, Windows syncs its software clock with a slightly more accurate hardware clock affixed to your motherboard. Both the software and hardware clocks, however, are flawed.

A number of software utilities, including ClockWatch and Time Synchronizer, can synchronize your PC with NIST's atomic clock.

You can always reset your clock manually, but it will again drift noticeably out of whack in a matter of days.

"Getting the time wrong is a cardinal sin when it comes to time synchronization," says Skip Singer, president of Beagle Software, which makes the time utility ClockWatch.