To run D-Time simply download dtime.zip and unzip it to your directory of choice. If you do not have Sun's Java 2 (tm probly) installed you will have to download and install this before running D-Time.
Java 2 can be downloaded from java.sun.com. Get the US-english version and save yourself a few megabytes, the application doesn't use any internationalisation anyway.
When Java 2 is installed and configured you can run D-Time simply by double-clicking the self-executing file DTime.jar.
In addition to DTime.jar and the necessary image and configuration files, dtime.zip contains installation instructions (this file), a help file (help.txt), application history (history.txt) and an icon (DTime.ico) you can use with your DTime-shortcuts, if the standard icons annoy you as much as they annoy me.