How to set up robust Windows time synchronization?

I have an incorrect time on my Windows machine. I'm not sure how to specify the proper timezone and setup an NTP synchronization. When I'm using a dualboot configuration with Linux (Ubuntu) my time is getting off by two hours every time I boot Windows.

How do I set up a robust time synchronization on my Windows 8 OS?

Answer

The answer is actually timezone differences - See this:

https://help.ubuntu.com/community/UbuntuTime#Multiple_Boot_Systems_Time_Conflicts

Operating systems store and retrieve the time in the hardware clock located on your motherboard so that it can keep track of the time even when the system does not have power. Most operating systems (Linux/Unix/Mac) store the time on the hardware clock as UTC by default, though some systems (notably Microsoft Windows) store the time on the hardware clock as the 'local' time. This causes problems in a dual boot system if both systems view the hardware clock differently.

The advantage of having the hardware clock as UTC is that you don't need to change the hardware clock when moving between timezones or when Daylight Savings Time (DST) begins or ends as UTC does not have DST or timezone offsets.

Changing Linux to use local time is easier and more reliable than changing Windows to use UTC, so dual-boot Linux/Windows systems tend to use local time.

Since Intrepid (8.10), UTC=yes is default.

Make Windows use UTC:

Note: This method was not initially supported on Windows Vista and Server 2008, but came back with Vista SP2, Windows 7 and Server 2008 R2.

To make MS Windows calculate the time from the hardware clock as UTC.

Create a file named WindowsTimeFixUTC.reg with the following contents and then double click on it to merge the contents with the registry:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
     "RealTimeIsUniversal"=dword:00000001

Make Linux use 'Local' time:

To tell your Ubuntu system that the hardware clock is set to 'local' time:

1. edit /etc/default/rcS


2. add or change the following section

#Set UTC=yes if your hardware clock is set to UTC (GMT)
UTC=no

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