As you make your way around the world or simply across the country, you may want your calendar appointments to shift to match your current time zone, or you might need them to stay fixed no matter where you are -- fortunately Google Calendar lets you switch between both options if you delve into the settings for its mobile apps.
On Android, dive into the Settings entry on the main app menu then choose General and Use device's time zone to toggle the feature on and off. Over on iOS, the process is exactly the same except you get a cog icon in place of the Settings entry. With the device time zone option disabled, it's possible to choose one manually via the drop-down menu underneath. There's no such option for Google Calendar on the web, though you can configure additional time zones through the Settings page.
What difference does it make? Say you're setting up a video link to a meeting back in the office while you're on the other side of the world -- with this setting enabled, you see the local time you need to be online. If it's switched off, you can see the time it's going to be at home for the other people you're chatting with. Both options can be useful, and it's handy to be able to switch between them.