Dual boot Windows and Ubuntu?
Windows defaults to "Local" time. Ubuntu defaults to "Universal" time.
Current versions of Windows can be switched to Universal, but not older versions.
It might be easier to just switch Ubuntu to Local!
To view the current time zone status:
timedatectl
You will see the current time in Local and Universal.
Look for this line near the bottom:
RTC in local TZ: no
Change the system to Local time:
sudo timedatectl set-local-rtc 1
Change the system back to Universal time:
sudo timedatectl set-local-rtc 0