Real-Time connects to a Real-Time server through the internet, or across a LAN, updating your computer's system clock according to the system clock on the server it is connecting to. So in other words, it is like a radio-controlled alarm clock. Where the radio-controlled clock automatically updates its time display when it receives a signal through its built-in radio, Real-Time updates your computer's clock through the Internet.
Easy to set up. I like the way you can set it to update the time regularly, after as many hours as you like. Really useful especially since the one built into windows xp stopped working for me.