I'm having a really funky time issue with Windows 10 at the moment, that I've never experienced before. It is really baking my noodle.
I noticed last night that my Windows clock was out of sync, which is unusual. It seemed to be about an hour behind. I didn't think much of it at the time and just hit the sync button to correct the time.
Today when I booted my PC after coming home from work the time was completely messed up, saying something like 9:XX PM when in reality it was around 4 PM. The date was correct if I remember correctly. I synced the time once again and went for a walk with my wife and kids. A couple of hours later the clock was off once again by roughly 30 minutes.
Now I've monitored this a bit more closely and time seems to desync/change suddenly instead of gaining/losing time gradually.
At 6:56 PM the clock jumped back to 6:24 PM at which point I sync'd again. Following 7:59 PM the clock changed to 7 PM instead of 8 PM. At 9:21 PM the clock changed to 8:21 PM, losing exactly an hour again. WTF?
Date is never lost, only time jumps around. I've noticed no other weird system behaviour and malware scans come up clean.
Can a CMOS battery result in this weird behaviour? Because I put in a new CMOS battery just last year where the old one died - it was a clear cut case because the UEFI BIOS had to be reset due to lost settings every time I powered on the computer before it would boot. The PC otherwise worked flawlessly with the dead battery for a few days until I put in a new replacement battery that fixed the issue.
I've tried all the bla bla bla unregister/register WT32 dlls and services. Set the Windows Time Service to automatic. Changed time.windows.com to time.nist.gov. - and I'm still temporally challenged in Windows.
What to do?
Edit: And... at around 10:28 PM the clock lost precisely an hour again.
Edit 2: I powered down my PC 0:23 AM (power off at wall socket as well, like I always do) and this morning I entered the BIOS before loading Windows and the time was 0:23 AM with the correct, current date. So time did not update at all, but it's not like it is losing the date or other BIOS settings. Dafuq?
I found a very old cnet thread with the exact same issue. Unfortunately there's no final update or resolution.
https://www.cnet.com/forums/discussions/date-time-doesn-t-update-when-computer-is-turned-off-548455/
Edit 3: It looks like I might have resolved this Chrono Conundrum. I'm not entirely sure what exactly was wrong, but I took out the CMOS battery and replaced it with a brand new one after 5 minutes of leaving the system without a battery. I loaded the optimised default settings in the BIOS and booted the system. Now my PC hasn't lost time in over 4 hours. Maybe it just needed a time out/reset, I'm not sure the change of battery was necessary as the old one was just a year old - but since I took it out I could just as well stick a completely new one in there.