"PerfectClock is a skinnable, flexible, fast and highly customizable program displaying an unlimited number of World-Time clocks on your desktop."
This is a version made for linux
Perfect clock skins are designed by ALSEDI Group (www.perfect-clock.com), the linux version of Perfect Clock was created by Helder Fraga aka Whise
This linux version was created from reverse so you may not get all the features you get with the windows version
you can get new skins at http://www.perfect-clock.com/index.php?page=download-skins