If they are both on a Mac, I understand there might be a problem with the clocks. Because of the ways each system handles the system clock, I believe you have to wait for the PC to reset the clock after rebooting with Boot Camp... and vice-verse into the Mac. The Mac checks the clock on boot up. The PC apparently doesn't but instead does it on a schedule something like every half hour. Parallels will use the Mac clock.
Microsoft will have an update for handling the political driven change in daylight savings time. I wonder if MS will update W98, W2000, WME, etc.
There's been patches out for the DST clock thing for months for at least Windows 2000 and up. I haven't checked about W98 or prior since I don't have any users on those antiques.
But then again, Apple doesn't have a DST patch for System 6 or 7, either.