You might be looking to put plans in place in case your timetable changes.
Although it isn't possible to create backup timetables in Arbor, you can create one in TimeTabler, to import into Arbor.
You can keep this backup file on hand until it's needed, should the situation arise.
Important things to consider
Are the courses the same between the two timetables?
If the courses will not be the same, you'll need to end student enrolments into your current courses, and once you've imported the new timetable, enrol students again.
Please note that using the bulk tool will not end or override their existing enrolments, so you would need to end the old enrolments for each course.
If you use teaching groups, you could end the automatic enrolments into the old courses and add new ones into the new courses.
Should we delete our old course structure?
You might want to consider whether to keep your original course structure in Arbor (just without any lessons scheduled), in case you choose to move back to your original timetable later in the year.
You will also want to consider the implications that changing course enrolments will have for the setup of your assessments. If you import brand new courses, you will need to click into each of your assessments from Students > Assessments > Annual Policy > Manage Assessments to add the new courses.
If you do need to import your backup timetable
If you do need to import this new timetable at any point, make sure you end the current timetable in Arbor first. Follow the instructions in the Actions to complete before importing section here: Importing a timetable from TimeTabler