The problem is that Linux uses UTC and Windows uses the local time from the RTC. This means whenever you boot Linux or Windows and then go back to the other OS, you will find your time is incorrect because of the two different clock modes fighting.
This results in very annoying issues when booting between the two because the clock is set based on the different standards once you boot (eg. Linux UTC by default and Windows RTC). For example it may cause issues with fsck and........