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When I boot the Lion OS the date setting is correct but the time is not.

The way I correct this is by selecting 'Open Date and Time Preferences', check the 'Set Date and Time Automatically' checkbox and select my region. The correct date and time is set.

The only problem is that when I restart my Mac the time setting has changed and is incorrect again, even through my region is still selected. I repeat the process above upon each reboot to rectify.

I reboot often as I am using Bootcamp 3.2 to run Windows 7.

Does anyone know why the time is changing and how I can fix the problem permanently?

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up vote 4 down vote accepted

Yes, Windows and Mac OS calculate time in a different way, and so clash when dual-booting. The bootcamp drivers should include a little file called Appletime.exe which is supposed to fix any time sync issues between Windows and Mac OS.

If this file is not present or not running, you can manually install it from here:

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Windows and OS X calculate the time from the system time differently, which leads to discrepancy when you switch between them.

If the Boot Camp drivers aren't taking care of the problem, it is possible to fix by adding a registry key instead.

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