Troubleshooting guide
How to fix the problem
Windows and Linux can interpret the hardware clock differently: as local time or UTC. Then after the switch the hours are shifted even though the time zone is correct. First, distinguish this case from poor RTC power supply.
Possible solutions
Choose the method that matches your situation. Start with the simplest suitable option and check the result. If the problem is fixed, you do not need to continue with the other methods.
Timeline and sync check
Check the simple settings on both systems.
Steps to follow
- In Windows Settings > Time & Language > Date & Time, select the correct time zone and enable time synchronization.
- Also select the same location in Linux time settings and enable network time synchronization.
- In the Linux terminal, timedatectl, if using systemd, shows the timezone and RTC in local TZ status.
- Switch between systems and note the offset. A precise shift of a few hours helps determine the difference in interpretation.
Selection of the uniform RTC principle
Choose one documented method and save the option to return.
Steps to follow
- Check your distribution's dual-boot documentation for recommended UTC or native RTC compatibility with Windows.
- Make a note of the current settings on both systems. Do not modify the registry with a random file from the forum.
- Standardize the RTC interpretation according to the selected official instruction; systemd warns about local RTC limitations, so consider DST as well.
- Check the time after booting into both systems and after a complete shutdown. If the date still disappears, go back to the RTC hardware check.
If the problem persists
If the BIOS date also disappears or the time returns to old years after a long shutdown, check the RTC battery or its circuit. If only the hours change when changing the system, match the clock interpretation of the two systems, not the hardware.
Request a repair