This is a curious case. What happens if you install a linux or any kind time-literate OS? If possible, of course. What gets me is that to this day those Redmond morons can not get it in their heads what kids in Berkeley did decades ago with elegance.
Yeah it is more of a mystery than bothersome. By the way the vacation is over, the clock is back to its normal time keeping. So this time it lasted a bit over 3 days.
Have you checked the BIOS version out per Mr Morse's suggestion? An intriguing case of 2 devices from the same mfg exhibiting the same symptom.. Was Lenovo good for anything in regards to support (in case you tried that route)? A case of swinging privilege and authority in my understanding.