Ubuntu – Ubuntu 18.04 cannot set hardware clock as local time

I had a Ubuntu 18.04.1 machine dual boot with Windows 10, and these two OS has time conflict. Previous on my machine with ubuntu 16.04 this conflict can be easily solved with timedatectl set-local-rtc 1 — adjust-system-clock, but this command does not work any more on my Ubuntu 18.04 system.

Here is the terminal output:

yunhui@hp:~$ timedatectl set-local-rtc 1 --adjust-system-clock
yunhui@hp:~$ timedatectl 
                      Local time: Thu 2018-08-02 16:31:58 CST
                  Universal time: Thu 2018-08-02 08:31:58 UTC
                        RTC time: Thu 2018-08-02 08:31:58
                       Time zone: Asia/Shanghai (CST, +0800)
       System clock synchronized: no
systemd-timesyncd.service active: yes
                 RTC in local TZ: yes

Warning: The system is configured to read the RTC time in the local time zone.
         This mode can not be fully supported. It will create various problems
         with time zone changes and daylight saving time adjustments. The RTC
         time is never updated, it relies on external facilities to maintain it.
         If at all possible, use RTC in UTC by calling
         'timedatectl set-local-rtc 0'.
yunhui@hp:~$ grep -i utc /etc/default/rcS
grep: /etc/default/rcS: No such file or directory

Basically Ubuntu knows I have change to interpret hardware clock as local time, but the RTC time is still Universal time. Also the “rcS” file does not exist, but I have tried manually create the file and write “UTC=no”, still no luck.

Does somebody know how to solve this problem?