The timer display shows your current activity.
As you move from one open file to another the timer will show each file's timed values.
Each user in a multi user installation is recorded separately for each file. Today displays the amount of time you've worked on the file for that day only.
When you install CadTempo you will be asked if you want to include a desktop and start menu shortcuts to display this window.
CadTempo starts automatically when a user starts the computer or logs on.