How do I use the World clock on my Nokia device?

The World clock tab will allow you to check the time in different cities. Select Menu > Office  (or Applications on some devices) > Clock and scroll right to the World clock.

To add a city to the world clock view, select Options > Add city.

To change the city that determines the time and date in your device, select  Options > Set as current city (or My Current city on some devices). The city is displayed in the Clock main view, and the time in your device is changed according to the city selected.