System time synchronized with hardware clock

Copper Contributor

I have two PC, its OS is Windows 8.1 embedded. I don't connect it to internet, set the time zone"(UTC+10:00)Canberra, Melbourne, Sydney", disable daylight time. At 2021-10-4 , I adjusted the time  from 10/4/2021 3:23:42 PM to 10/4/2021 4:23:01 PM , but at 2021-10-24, it adjusted the time  from 10/24/2021 2:45:32 AM to 10/24/2021 1:45:23 AM itself. I looked up Windows events, it says:


"The system time has changed to ‎2021‎-‎10‎-‎24T09:45:22.500000000Z from ‎2021‎-‎10‎-‎24T10:45:31.235292400Z.

Change Reason: System time synchronized with the hardware clock."

10/24/2021 5:45:22 PM


Who can tell me why it happened? Is it because the hardware clock using daylight ? but there is no settings  in BIOS to do this. Or when I changed the time at 10/4/2021, it didn't  synchronize with the hardware clock , it changed back 20 days later? 

2 Replies


Hello! You've posted your question in the Tech Community Discussion space, which is intended for discussion around the Tech Community website itself, not product questions. I'm moving your question to the Windows 10 space - please post Windows questions here in the future. 

Who can help me with this issue?