I started doing this a few years ago when I began bidding actively on eBay, including doing a little bit of manual sniping: I synchronized my clock with one of the many time servers around the country. These servers are synchronized to an atomic clock, and while there is some latency (the time it takes the electrons to travel from a time server to your computer), you still will have your PC clock synchronized well within a quarter second of the "official" time on these servers. Ebay also synchronizes the clock on their network. They do not say this anywhere online that I can tell, but in the past, I'd noticed while refreshing auctions and watching when items expired, their time was aligned with what I was seeing on my end. Plus, from a legal standpoint, it only makes sense that eBay keeps their time synchronized to a standard. If they aren't perfectly exact, in my experience they were usually well within a second. For years I used a little program called Dimension 4. Unfortunately, it was never compatible with Windows XP (XP handles internet connections differently), but in my Win98 days, it would synchronize my clock regularly, several times a day if I wanted. Windows does have a time synchronizer built into it, but it not only checks the time at a laughable period of once a week automatically, most of the time it would fail to synchronize at all. Weeks would go by without my computer being synchronized! And I would often see my PC's clock drift off the correct time by several seconds per day, if not more. Today I found a new freeware utility to synchronize a Windows-based computer with any internet time server: http://sourceforge.net/projects/nettime/ As it installs, it chooses up to the best five time servers from a list of over 120. From there, you can specify the number of seconds between synchronizations...I set mine to check the time every 900 seconds (15 minutes). Since I have a cable modem, I can leave it on all the time. It runs as a service in WinXP (and Win2K as well) and you can even hide the system tray icon so it runs invisibly. If you are on dialup, you may want to run this manually. A neat feature is that it can check up to five servers. If it only connects to one, it still corrects your time. If it connects to two or more, it averages the time, and it will throw out any one time received that is too far out of range (considered "bogus" by the program). When I was manually sniping auctions, I'd open up my clock in Windows. (In XP, double-click on the clock in your system tray.) Then I could follow an auction's ending time, and figure our how many seconds before the end that I could safely snipe an auction at. The only caveat: if you are using a router, you may have to enable the proper port(s) so your computer can connect to the server and retrieve a response. Other than that, this is a painless little program to install, and is useful even if you never visit eBay.