World Time Clock

This world time clock designed by Charlotte van der Waals is a very simple and equally smart design to show the 24 different time zones around the world on one clock. The clock is barrel-shaped with 12 sides, each side having two cities written on it that are 12 hours apart. The clock face tells you the current time in whatever city is written on top as the clock is rolled over.

There's no minute hand, however, since every rotation of the clock would move the minute hand five minutes forward or backward every time.  If someone could create a simple solution to this, now THAT would be excellent design.

source: via Slipperybrick