Looking for help for correction of Windows clock loosing time during shut down period

[ubhattacharjee.65]

I am using Windows 10 build 1803 updated upto 8:45 AM today. Windows clock is found to be losing time when it remains shut at night. If I shut it down at 11 PM with right time in the taskbar clock an start it at 8AM next morning I find the clock is lagging about 6 hours. I adjust the time according to correct time and it goes no the wholw day till I shut it again. This is happenning for the last 15 days.
Incidentally, I have a dual booting system with Linux Mint 19 Cinnamon . In Linux no such time Lag is found at the start if I start it at first.
My mobo is GA-B85M-D3H , Processor i-5 @ 3.10 Ghz, RAM 8GB, HDD 1TB. I have three equal sized Partitions. C: is housing Windows 10, D: Linux Mint E: General Storage.
Please help me to correct the clock problem. Incidentally I am a great novice and have no idea about programming in windows or in Linux.

 

[SkyNetRising]

Replace CMOS battery.

 

[kerberos_20]

yout battery is dead or is about to die.
check your mainboard, there should be round battery, on it should be written type of that battery, go to shop and buy new one (same type) its mostly cr2302 but just be safe and make sure its same