A simple but useful option available in Windows 7, which many may not be aware of, is the ability to display up to 2 additional time zones via the System Tray Clock. Living in Oz and continually battling the time differences, I have found this to be particularly helpful.
Here’s how:
Left click on the time display in the System Tray and select “Change date and time settings” or right click on the time display and select Adjust date/time:
Now click on the tab for Additional Clocks. Place a checkmark in the little box next to “Show this clock” and then select the appropriate time zone. Give the clock a suitable name and when all finished click Apply, OK:
Hover your mouse cursor over the system tray time display and you will now see this:
Left click the time display to see this:
Thanks for this tip, I too have trouble remembering time zones for London and Perth WA.