Back in the AT days (286, 386, etc.) the clocks often had an adjustment resistor or capacitor and you could tune it in yourself if needed. Now they are fully integrated and the best you can do if they gain or lose time is resync with a known good reference.
. There are lots of free utilities that do this. Many use the national atomic clocks at one site or another. Just go to a site like download.com, search on- clock setting -and you'll find a slew of 'em. There are some that can actually learn over time what your clock's error rate is and then automatically readjust at preset intervals - just read the descriptions as I'm not sure of the names off hand. There is a tool in VCom's SystemSuite 5 (and possibly FixIt 5) that does this just in case you already have one of them.- may be the same thing in other utility suites.
. I found that mine are off less than a 30 sec. a month. Just lucky I guess...
.bh.