Do any schools maintain records of when instructors arrive and depart the classroom?
I thinks it depends if the instructor is Tenured, part time or a contract instructor. For the later two, I would believe that the school would have some time sheet system for payroll purposes. Its becoming common. 
Temple university has a template for time sheet for instructors
http://www.temple.edu/cjtp/pdfs/Instructor%20Timesheet.pdf

Also, check out this link

http://www.nj.com/news/index.ssf/2011/02/kean_university_now_requires_f.html