Since Windows Vista, Windows users have had the ability to add clocks. I’m in the U.S. Central time zone and have no problem thinking about scheduling meetings with people in the Eastern and Pacific time zones. Hyderabad is a different matter because of the half hour. London is easy except right now when the U.S. is on Daylight time and the U.K. is not.
You can add two clocks using the Additional Clocks tab in Date and Time.
Figure 1. Additional Clocks tab.
Figure 2. Mouseover after adding clocks.
Figure 3. Left mouse click in System Tray after adding clocks.
While the extra clocks are interesting, I personally find Hyderabad needs more visibility. Go to Gadgets and either double-click the clock or right-click and select Add to add it to your desktop. Set the Options for the clock to assign a name to it.
Figure 4. Clock gadget.
Figure 5. Use Options to put a name on your desktop clock. Either right-click the clock and select Options or click the wrench icon.