Time Zone Icon shows you at a glance the time of various time zones without any annoying program running in the front, because the clock is located in the top of the menu bar. You can add more than one place to the menu bar and get with one click the time information. It also shows the the current temperature and weather conditions of that place. Despite that the app offers a separate time zone calculator, where you can manually enter times to figure out this time in another time zone.
Time Zone Icon can show you the following information: