ZoneAlarm versions 10.x or greater.
You can find the number of days remaining on your license from inside the ZoneAlarm software.
Open ZoneAlarm by double clicking the 'Z' icon in the system tray in the lower right hand corner of your screen.
In Windows 7 the icon may not be visible, you will need to click on the arrow pointing up in the system tray to see the 'Z' icon.
When ZoneAlarm is open you can see the number of days remaining in the lower right hand corner of ZoneAlarm and it will say how many days you have left in green or red colored text.