On-Time Atomic Clock Sync
Synchronize your PC's clock with internet atomic clock servers
http://calendarconstructer.com/on_time_atomic_clock_sync.exe - 420Kb - Download - Screenshot

#1 Atomic Clock
Atomic Clock lets you synchronize your computer's clock with any Internet atomic clock (time server). It uses a high-precision network time protocol (NTP) which provides accuracy of several milliseconds depending on the characteristics of the synchronization source and network paths. ... Features: Skinned, Work as Time Server, Synchronize Periods, Import Time Servers List!
http://www.freefileszone.com/atomic-clock/download/acdemo.exe - 488Kb - Download - Screenshot

2D_Gold_Clock Screensaver
Synchronize your local PC time using the Atomic Clock servers. Collection of various analog clock with synchronization your local PC time using the Internet(Uses the National Institute of Standards and Technology (NIST) Atomic Clock servers). Choosing various dial, various arrows, choosing... The most different variants of clock on every day! ... Having switched on a casual choice you receive new clock at each start.
http://www.all-sweets.com/download/2d_gold_clock.exe - 468Kb - Download - Screenshot

PresenTense NTP Auditor
PresenTense NTP Auditor monitors your computer's built-in clock and compares it's time to the real time. Most computer clocks lose or gain time so within a few days, your computer does not show the real time. Many software packages claim to synchronize your computer to atomic clocks or satellite... PresenTense Auditor allows you to monitor and record your computer's time and graph the difference between it and up to three national reference clocks on the internet. ... The full version even supports printing running logs to a line printer.
http://www.bytefusion.com/download/bin/ptademo.exe - 2Mb - Download - Screenshot

GPS Time and Test
It is a PC Clock synchronization program. The program synchronizes a PC Clock to the right time using artificial satellites. It is alternative solution to synchronizing with atomic clock using NTP(SNTP) and Internet. The program works in the interactive mode or in background. ... The product is free for users of BrigSoft products Atomic Clock Service, PC Atomic Sync and OS Non-Proxy Atomic Sync. ... Default protocol version is NMEA 0183. ... It outputs a port receiving buffer, extracts all NMEA sentences and counts check sum errors.
http://www.brigsoft.com/atomic-clock-sync/download/GpsTimeInst.exe - 447Kb - Download - Screenshot

ClockDummy!
ClockDummy! is an atomic clock, which can say the time with a real human voice, and enhance your standard taskbar clock with custom graphics, month, and seconds. ClockDummy! also keeps your clock updated to the exact second via an atomic clock Internet server for any time zone and location, and... lets you select from a range of predefined styles for how your taskbar clock should look, or select your own graphics and fonts to use. ... is the ultimate addon to the standard taskbar clock and it's easy to use!
http://www.dummysoftware.com/ClockSetup.exe - 1Mb - Download - Screenshot

Trouts Talking Internet Clock
* Liven up & personalize your desktop with an Analog Clock face using any picture you like * Add an analog clock to your system tray * Remember Birthdays, Anniversaries, Appointments, Meetings etc with a Message, Song, Multimedia Presentation or a Microsoft Agent character * Set applications to... * Dynamic Icons -Trout's Internet Clock's icons are functional clocks. ... * Customizable Language Support means you can easily change text and hints on TICs windows either to another language or to your own cooler wording.
http://chemware.co.nz/tic23_sw.exe - 947Kb - Download - Screenshot

12Ghosts Synchronize
Synchronize your PC time with an atomic clock via the Internet. This program simplifies the task to the outmost and sits conveniently to access in the startbar tray. 12-Sync adjusts the time repeatedly, automatically, and silently exactly on the dot. ... It waits for an Internet connection, then adjusts your clock at atomic precision, without your interaction. ... You will never have the wrong time again! ... It keeps a log file about all activities that you can limit to size or age.
http://12Ghosts.com/download/12sync.exe - 2Mb - Download - Screenshot

AtomSync
AtomSync is a utility that works in the background and periodically checks your system time against an internet NTP time server or against a computer in your LAN (local network) which runs an AtomSync LAN time server. It also displays a nice graphical clock with time and date on your desktop and... the AtomSync is German an means atomic clock) lets you synchronize you computer or lan with the nation's reference time over any internet connection and with a precision in the milliseconds range. ... Internet time servers usually deliver an extremely precise time which is often synchronized...
ftp://ftp.emtec.com/atomsync/atomsync.exe - 904Kb - Download - Screenshot

1st Atomic Time
1st Atomic Time keeps the system time accurate on your computer or any computer in your network. It synchronizes your PC clock with Internet atomic time servers. You can pick the fastest and most reliable servers from the built-in list of more than 150 choices or add your own. ... 1st Atomic Time hides in a small icon near the taskbar clock and does not require desktop space. ... You can configure 1st Atomic Time to operate as a time server. ... 1st Atomic Time can adjust the system time correctly even if you have irregular Windows time zone settings.
http://www.atom-time.com/download/1st-atomic-time.exe - 707Kb - Download - Screenshot