Band Lesson Schedule On Google Sheets

I am middle school band director and I am thinking that instead of me taking time to write out a lesson schedule I might make a lesson schedule on google sheets and have students pick there times.  Almost always there is a lesson schedule change because of a student not being able to miss a certain class.  I think that if I do this I won't have to do as many rewrites of the lesson schedule.  The only thing that worries me is whether students will move other students lesson times.  I am trying to figure out what type of securities are available so that I can make sure that doesn't happen.