Different time in Windows and Linux Mint

Question

I installed Linux Mint first on my Acer Aspire 4930 and then dual booted with Windows 7. I see the correct time on Linux Mint but on booting into Windows the time is shifted back by a few hours, even after re-setting the time on rebooting it shows the wrong time again. Why is this happening?

Answer 1

On Windows, the system RTC clock is traditionally kept in local time. In Unix and Linux, it's traditionally kept in UTC, and /etc/localtime is used to indicate the current timezone so that the displayed time is correct.

These two worldviews collide in dual-boot configurations, because there's only one RTC. Usually you tell Linux to assume that the RTC is local time (because Windows can't be told). This varies from one Linux to another, but since Mint is like Ubuntu you can probably set UTC=no in /etc/default/rcS. Then you can set the clock to local time in Windows and Linux will leave it alone after that.