With GPS functionality being present in more devices these days; Apple decided to give Snow Leopard the functionality to automatically adjust the time zone on your computer based on your location.

Enabling this function is easy. Just go to System Preferences and click on the “Date and Time” section. Under the Time Zone tab, check the “Set time zone automatically by location” option. The map should turn grey, and your Mac will start automatically determining your current location using the CoreLocation service.

I’m sure it won’t take long before they are, but Mac’s aren’t yet being sold with a built in GPS chips. Your Mac won’t have GPS functionality unless you add it. However, the CoreLocation service will use your computer’s visible Wi-Fi networks and check them against a database of the WiFi’s registered locations.

If you’ve connected a GPS device to your Mac and it Snow Leopard recognizes it, the CoreLocation service should automatically use your GPS to determine its location. With the GPS connected you can pretty much take your computer anywhere in the world and OS X will automatically adjust your time to the local time for you.

When the CoreLocation service is using WiFi networks to determine your location you’re going to be a lot more limited on where you get this automatic functionality.

Other applications can use CoreLocation service through OS X too. We wrote about Google Latitude earlier (Google Latitude – It’s a GPS Without a GPS – Sort Of) and it will ask for access to your Mac’s CoreLocation service so you can share your location with your friends.

For security, an application will always ask permission to access to your location information. If you like, you can completely disable the CoreLocation service by going to the Security section of System Preferences and checking the “Disable Location Services” checkbox under the General tab.