Clicking on a button in the tool bar produces the following effect.
 
Minimize or Maximize the window.
 
Start recording time. A new time entry is appended to the list of time entries, and the button becomes the Stop button. The new time entry is the active time entry, and it is displayed in italicized text.
 
Restart the selected time entry. This button looks just like the Start button above except the minute hand is ten after the hour. This button is available when only one time entry is selected. The time interval between the stop time and when you restart is calculated as paused time.
 
Stop recording time. This button then becomes the Start button.
 
Pause recording time. This button then becomes the Resume button.
 
Resume recording time. This button then becomes the Pause button.
 
Total all time entries. This button then becomes the total marked button.
 
Total marked time entries. This button then becomes the total all button.