Why is my clock off by many hours when I boot into another operating system in a dual boot environment?

There may be a difference in the way each operating system interprets the system clock. Some operating systems interpret the clock using UTC (which is the Universal time zone, or Greenwich Mean Time) and calculate other timezones by adding or subtracting from the UTC time. Others interpret the system clock as local time.

If the operating systems differ in their interpretation, it can ca...