Short description of Atomic Alarm Clock 5.9: Alert yourself about important events with different alarms and replace your computer tray clock using different skins. Computer Alarm Clock that will play any MP3 file. It can also run a program, log off, reboot, shut down, or turn off. Atomic Alarm Clock is also an atomic-time synchronizer and advanced replacement for Windows tray clock. Over 130 skins are included in the distribution. It is supported by Longhorn clock style.