The internal rtc button battery must be exhausted, replace it.
During shutdown the current time is stored in the rtc, to be used at the next power up; as it looks that it can't be done, the shutdown blocks -- this is your other problem and causes the need to unplug the box, leading to the wrong time.
To solve the 3 days in the future problem, as the normal fsck doesn't solve it you have to use the "force fix" (fsck -y).
You might also try to adjust the time to the one fsck expects, and then trying to mount.