How to change Date & Time

Hi
I use Debian12  from LinuxCNC_2.9.pre-amd64.hybrid.iso
I have problem to change Time

I use cmd 
timedatectl set-timezone Asia/Bangkok
But, Time show on down right is local time 20:XX:XX
My location is  Asia/Bangkok = 13:XX:XX
How to use time 13:XX:XX

Second question....

Why default about  synchronized : no   ?  For save perfomance cpu ?

Asis

​​​​​​​ 

I don't know if this helps, this solved my problem after reboot:

MaHa wrote:

I don't know if this helps, this solved my problem after reboot:

timedatectl set-local-rtc 1 --adjust-system-clock

 

Wow !!!
This solution can help me, Thank you. ^^"