This means that most users never have to worry about setting the date and time in Windows, or correcting the time after events like power outages or a switch to daylight-saving time.But sometimes a user’s Windows clock can go awry and display the incorrect date or time, usually due to hardware issues, a temporary loss of Internet connectivity, or online synchronization problems.UPDATE 11/22: One thing that you should be aware of here: the rate at which the time in a virtual machine drifts is affected by the total system load of the Hyper-V server.More virtual machines doing more stuff means time drifts faster.In order to deal with time drift in a virtual machine – you need to have some process that regularly gets the real time from a trusted source and updates the time in a virtual machine.
Once inside the guest operating system – these time readings are then delivered to the Windows time keeping infrastructure in the form of an Windows time provider (you can read more about this here:
Windows will automatically sync with the time server again in 7 days, and as long as your PC doesn’t have faulty hardware, such as a drained CMOS battery, your local PC clock shouldn’t drift too much in the interim.
If you can’t connect to a time server for any reason, you can always manually set your PC’s clock by selecting Change date and time from the Date and Time tab of the settings window.
Instead they read the time from this clock once (when they boot) and then they use their own internal routines to calculate how much time has passed.
The problem is that these internal routines make assumptions about how the underlying hardware behaves (how frequently interrupts are delivered, etc…) and these assumptions do not account for the fact that things are different inside a virtual machine.