Change your timezone
Open the Activities overview and start typing System.
Select Settings ▸ System from the results. This will open the System panel.
Select Date & Time to open the panel.
If you have the Automatic Time Zone switch set to on, your time zone should update automatically if you have an internet connection and the location services feature is enabled. To update your time zone manually, set this to off.
Click Time Zone, then search for your current city.
The time will be updated automatically when you select a different location. You may also wish to set the clock manually.