I've encountered a problem with the way Parallels is handling system time. I can't get the guest's time to stay correct. I've tried each of the 3 clock settings Parallels provide and they all have bugs: 1. Sync from Mac OS X: The guest's time is randomly set to 4 hours in the past. It randomly fixes itself later on. (The guest doesn't indicate it's used NTP when it fixes itself). 2. Sync from either OS: Both OS's times are set to 4 hours in the future! 3. Do not sync: The guest's time is randomly set to 1 hour in the future. When I spot the guest having the wrong time, I use NTP and it fixes itself for a few minutes then becomes wrong again. I have Windows configured to store the CMOS time in UTC since this is the only way it has the right time in Boot Camp. Windows 7 Ultimate Parallels 8.0.18483 OSX 10.8.3 Mid 2012 rMBP