Check your current timezone using the following command,
Time zone files are located at /usr/share/zoneinfo. Navigate to this location and select the timezone file of your choice.
The currently active timezone will be stored in /etc/localtime, make a backup of this file,
sudo mv /etc/localtime /etc/localtime.bak
We can create a link,
sudo ln -s /usr/share/zoneinfo/Asia/Kolkata /etc/localtime
Now check the newly updated timezone
Note: You can change the timezones according to your physical location from the zoneinfo