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User profile for user: appcrasher
appcrasher Author
User level: Level 1
0 points

When dual-booting with Windows 7, Mac OSX time settings reset every reboot.

I have recently installed Windows 7 Professional on my mid 2010 MacBook Pro via BootCamp (Running Mavericks BTW). Everything runs grean and have not experienced any problems on the Windows side, but I have a problem with Mac OSX now. When I am using Windows 7, and I reboot into Mac OSX, I find that my time settings are wrong. It seems like my time zone has changed, because the date is correct, as well as the minutes, but the hour is always wrong. When I go to Date & Time in System Preferences, and my time zone is correct, but I still have to chage the hour in the time. Any ideas as to why this is happening and how to stop it would be greatly appreciated.

MacBook Pro, OS X Mavericks (10.9.1), Dual-Boot with Windows 7 Pro

Posted on Feb 21, 2014 11:17 AM

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User profile for user: Virdel MacSeeder 2014
Virdel MacSeeder 2014
User level: Level 1
4 points

Posted on Jul 16, 2014 2:54 AM

If you dual boot your Windows PC with OS X or Linux, you may have experienced a problem in which your clocks reset themselves incorrectly every time you boot into Windows. Here's a simple registry edit to fix that.

Essentially, the incorrect clock setting happens because OS X and Linux use GMT time while Windows tries to synchronize with your local time zone, getting confused when you reboot between the two. Apple's own Boot Camp drivers for Windows are supposed to fix this problem, though some users have noticed that it still happens even with the drivers installed, and some Linux users are left out in the cold. Furthermore, if you have a Hackintosh, you can't install the Boot Camp drivers, so you'll need to find another way around the problem.

To fix it, just hit Start and type 

regedit.exe
in the search box. Hit Enter and navigate to 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
. Right click anywhere in the right pane and hit New > DWORD (32-bit) Value. Name it 
RealTimeIsUniversal
, then double click on it and give it a value of 1.

Lastly, reboot into OS X, then reboot back into Windows. You should now notice that your clock actually displays the correct time.

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User profile for user: Virdel MacSeeder 2014
Virdel MacSeeder 2014
User level: Level 1
4 points

Jul 16, 2014 2:54 AM in response to appcrasher

If you dual boot your Windows PC with OS X or Linux, you may have experienced a problem in which your clocks reset themselves incorrectly every time you boot into Windows. Here's a simple registry edit to fix that.

Essentially, the incorrect clock setting happens because OS X and Linux use GMT time while Windows tries to synchronize with your local time zone, getting confused when you reboot between the two. Apple's own Boot Camp drivers for Windows are supposed to fix this problem, though some users have noticed that it still happens even with the drivers installed, and some Linux users are left out in the cold. Furthermore, if you have a Hackintosh, you can't install the Boot Camp drivers, so you'll need to find another way around the problem.

To fix it, just hit Start and type 

regedit.exe
in the search box. Hit Enter and navigate to 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
. Right click anywhere in the right pane and hit New > DWORD (32-bit) Value. Name it 
RealTimeIsUniversal
, then double click on it and give it a value of 1.

Lastly, reboot into OS X, then reboot back into Windows. You should now notice that your clock actually displays the correct time.

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User profile for user: Virdel MacSeeder 2014
Virdel MacSeeder 2014
User level: Level 1
4 points

Jul 16, 2014 3:06 AM in response to Virdel MacSeeder 2014

In addition to the last reply on this thread, please name the DWORD value RealTimeIsUniversal correctly. Make sure there are no spaces before and after the word, and must use uppercase and lowercase letters together. If your Windows operating system type is 64-bit, try first the DWORD (32-bit) value. Then reboot. If it doesn't work, reboot back to Windows and then use DWORD (64-bit) value.

Hope this can help. Thank you.

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When dual-booting with Windows 7, Mac OSX time settings reset every reboot.

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