Do you want to know the time of the city where your relatives are living? Or do you want to do know the time of the city where you want to do business? If yes, then you need to set up a time zone. By default, this feature is disabled in both Windows 7 and Vista. The feature allows you to display up to two additional clocks.
Simply right-click on the clock in the System tray and choose Adjust Date/Time.
Now click on Additional Clocks tab, and start setting up your time zones. I have set Pacific time and Honk Kong time for myself as you can see from the screenshot below.
After you are done, click OK. Now move your mouse pointer over the time shown in the System tray bar and you will see different time zones that you have set.
Sadly, both Windows 7 and Vista supports only two time zones, if you want to set up more than two time zones, then you will have to install some 3rd party software.