Often it is a concern that the system clocks on your web server(s) and/or database server(s) might go out of sync after varying amounts of time. If your servers are not in sync, it might be difficult to analyze log traffic, errors, and other system events.
Windows has been known to lose clock ticks based on how heavily the server is being bombarded by CPU-intensive tasks. The best way to ensure that your servers keep consistent time is to use an authoritative time server, such as tock.usno.navy.mil. For information on setting up your servers to synchronize with a military clock, see
KB #216734 (Windows 2000) and
KB #314054 (Windows XP/.NET).