Mac: We still like Clocker, the free time zone clock for your menu bar. But if you have to track a lot of time zones on your Mac, you should also look at Menu World Time, another free menu bar world clock with a slightly different interface.
Menu World Time displays an icon to represent day or night in the menu bar, and an arrow to show if the other time zone is a day ahead or behind your local time. (You can also display the day of the week.)
But most importantly, its compact drop-down menu can display a long list of other time zones.
You can customise time zone labels, so instead of “Tokyo:”, “London:” and “Paris:” you can enter the names of remote workers on your team, or long-distance friends. You can also sort the different clocks manually, alphabetically or by current time.
If you spend a lot of time talking to people around the world, this is a tidy way to keep track of everyone’s time of day.
Unlike Clocker, Menu World Time doesn’t include support for calendars or reminders. If you don’t need those features, its simpler interface is actually a better option.