I found a solution to this whole thing. The problem with the Windows clock being off is because the hardware clock (the one on your actual motherboard) is being set to "Universal" time, or GMT, when you shut down your MacOS bootup.
When you boot Windows, Windows assumes your clock is set to your local timezone because that's what Windows does by default. This explains why the people who set their MacOS clock to GMT got the right time in Windows... If the hardware clock is being set to "GMT," when it's actually the local time, Windows will pick this setting up as local time as it did before.
To fix this, you need to add a key to your Windows system registry to tell Windows that your hardware clock will always be GMT.
*** WARNING: Editing your registry improperly can render your Windows
installation inoperable. Proceed VERY carefully. I am not responsible if you mess something up. ***
The short solution for people who know how to edit the registry:
A DWORD key called
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\R
ealTimeIsUniversal needs to have the value of "1"
The step-by-step solution is as follows:
1. Boot Windows
2. Click Start --> Run and type regedit. Click OK
3. The Windows Registry Editor should pop up. Navigate within the explorer to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
4. Click on the TimeZoneInformation "folder" from the navigation pane if you
haven't already done so.
5. This assumes the correct key doesn't exist. If it does, you will just change the existing key's value: Right click on the white space within the folder (If you don't have a right mouse button, you may need to download a program called
applemouse to emulate the "control-click" of the apple 1-button mouse). Select new --> DWORD Value. Title the key "RealTimeIsUniversal" (No quotes). Set the value to "1" (No quotes again). Hexidecimal should be fine.
6. Either reboot and set the clock in MacOS or set the clock in Windows. You should now be able to reboot into either OS and have a correct clock.
