有时间规定:
If you wish to extend your status date, you should apply 30 days before your status expires in order to do any of the following:
extend your visitor, student or work status
change the type of permit you hold (for example, from a student to a work permit)
change a condition of your permit (for example, if you are studying and you want to change schools, or if you are working and your want to change jobs)