Google Nexus 7 users can change the device time zone using the Date & Time option available as part of settings.
Step 1: Press the menu button to access the Home screen on Google Nexus 7
Step 2: Then tap the icon list on the Home screen. From the list of icons, tap the Settings icon.
You can also access settings screen using Quick links as shown below.
Step 3: In the Settings screen, scroll down to the Systems section and tap the Date & Time option.
Step 4: In the Date & Time screen, tap the Select time zone option.
This would display the following screen with the option to change the time zone.
By this way, Google Nexus 7 users can modify the time zone on their device.