AtomTime Pro

AtomTime Pro is a Windows application which will connect to an atomic clock time server via the Internet and fetch the current atomic clock time value.

It can then set your PC clock to the correct time.
AtomTime Pro is the latest sequel to the very popular AtomTime98 and AtomTime95. It works on Windows 95, Windows 98, and Windows ME, along with Windows NT 4.0, Windows 2000 and Windows XP. A partial list of the new features in AtomTime Pro include:
User-Defined Time Servers: The user can now define their own list of time servers. AtomTime will cycle through the list to locate an active server.
Message Logging: AtomTime can now log messages to a file detailing program operation, including time checks and error messages.
Dial-Up Networking: Improved Dial-Up Networking support, including the ability to use specific connections.
Time Adjust on Connections: The time can now be adjust each time a Dial-Up Networking connection is formed.
System Tray Date Display: The ability to display a date icon in the System Tray when running with an Update Interval. This date icon replaces the AtomTime icon.
Registry Settings: Settings are now saved on a machine basis, rather than a user basis as in AtomTime98.
Launch with Windows Start: A simple checkbox can now activate AtomTime on Windows startup.
Automated Operation: AtomTime Pro will run its automated updates even while the main display is open. AtomTime98 required that you close the display first.
Animated Icon: When an automated update is occurring, the AtomTime icon in the System Tray will be animated.
Time Formats: Support for more time formats.
Time Protocols: Time servers using port 37 are now supported.
Display Colors: The main display text can be changed from a color to black/white display.
Version Checking: AtomTime will automatically check for version updates on a regular interval.
Error Handling: Improved error handling and messages.