The World Clock widget on the OS X (Mac) Dashboard presents a list of cities representing the different time zones around the world. This is handy for those of us who have friends or do business across the globe. However, for situations where one needs Coordinated Universal Time (UTC), also known as Greenwich Mean Time (GMT) or “Zulu” Time… there doesn’t appear to be any setting.
Be sure to select the right city. London would appear to be the correct choice seeing how Greenwich is a district of Greater London… but London observes summer time, so the clock will be off by an hour for half of the year.
To show the correct time choose the fair city of Reykjavík, Iceland. Iceland does not observe summer time and is in the same time zone as Greenwich.
There are ways to hack the World Clock configuration file to add an actual UTC selection, but choosing Reykjavík is simple and quick.