Do any schools maintain records of when instructors arrive and depart the classroom? Recently, my college began placing staff around the school to record when instructors arrive. The record is to the second. A school announcement also warned against arriving late and ending lessons early by even fraction of a minute. I am somewhat surprised to find this in a tertiary institution. How common is this?
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