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KeesMacPro

macrumors 65816
Original poster
Nov 7, 2019
1,453
592
Hi,

After more than 2 decades without a Windows machine, I recently installed W10 (UEFI) on a Mac Pro 5,1 through OpenCore.
To my surprise I noticed the clock is always 2 hours earlier than the actual time when booted in Windows.

Although I've set Region and Time zone correctly , when I boot Windows the next day , same issue.
I've switched on and off : automatic time and automatic choise of region to no avail.
Nor did change the windows time server to another server change anything.
When I click "synchronize now" it shows the correct time.... until the next day.

I dont get at all how it's possible that an OS released in 2015 , is not capable of something so basic as showing the correct time...


I hope someone can help me out on this ,
thx in advance.
 

KeesMacPro

macrumors 65816
Original poster
Nov 7, 2019
1,453
592
Thx chabig, I appreciate it.
I'll dig deeper into this this weekend.
 

BigBlur

macrumors 6502a
Jul 9, 2021
641
704
Are you dual booting with MacOS? If so, that is likely the cause of the issue. MacOS and Windows interpret the system clock on the motherboard differently.

 
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KeesMacPro

macrumors 65816
Original poster
Nov 7, 2019
1,453
592
Are you dual booting with MacOS? If so, that is likely the cause of the issue. MacOS and Windows interpret the system clock on the motherboard differently.
Yes, this is exactly the case, thx a lot!
 

mi7chy

macrumors G4
Oct 24, 2014
10,495
11,155
I get this dual booting Linux and Windows. From memory, the short term fix was toggling one of the options in Windows 10 'adjust data/time'. Maybe this will help if you're running Windows 10.

https://itsfoss.com/wrong-time-dual-boot/

I've since installed Windows 11 Insider Preview and no longer see the time change dual booting Linux.
 

KeesMacPro

macrumors 65816
Original poster
Nov 7, 2019
1,453
592
From memory, the short term fix was toggling one of the options in Windows 10 'adjust data/time'. Maybe this will help if you're running Windows 10.
No, I went through all these options to no avail, but thx for chiming in.

The link @BigBlur posted worked perfectly and mentions dual booting Linux /Windows too btw : - )
 
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