ClockWatch - 1.4.0 

Synchronize your computer's system clock to the atomic clock over the Internet. You can adjust settings on demand or set a regular schedule with the results displayed in a graphical window.

HiClock - 1.7 

HiClock gives you an easy and thorough way to synchronize your system clock to the exact time using the Internet. It queries one of the National Institute of Standards and Technology timeservers, which then returns the correct standard time.

WorldTime - 5.0.1.455 

WorldTime lets you have from 1 to 10 configurable clocks, each with its own time zone, Daylight savings time rule, and description in a 12 or 24 hour display that minimizes to the system tray.

YATS32 - 7.4 Build 3 

This utility lets you automatically set your system clock to any of a number of time services available via the Internet or your corporate intranet. It supports multiple servers and time service protocols. It will even poll a list of different servers until it gets a valid time stamp. Included is an Internet Time Server Directory dialogue allowing direct selection from extensive list of national and international servers. Several enhancements have been made in this update. Now can run as a Windows NT service.