Comparing timetables
There are two options how to compare your timetable files. You may find both in menu File - Compare.
"Compare with last saved version" - it will compare your current timetable (the one you are currently working on) and its status on disk (that is the state when it was opened or last saved). It can be useful especially when you make some changes manually and you want to see what you have changed since last save.
"Compare with another file..." - this function will offer you to choose another timetable file and then it will compare it with your current timetables.
After invoking this function program will veil current timetable and will highlight only those cards which are on different position in timetable you are comparing it with. In bottom of screen you will see list of changed items:
Note: Both functions will display just the changes in cards positions and names of subjects/classes/teachers/classrooms. It will not show you changes in constraints.