Whether you are a visitor, a student or a foreign worker in Canada, it is essential that you maintain a valid status in Canada.
As a visitor, a border services officer at the port of entry in Canada will determine how long you can stay in Canada. Most visitors are allowed a six-month stay from the day they entered Canada. If the officer authorizes a stay of less than six months, they will indicate in your passport the date by which you must leave Canada. You may extend your stay by filing an extension before the expiration of your valid entry.
As a student, if your study permit expires before you have completed your program of study, you will need to apply for a renewal. You should apply for a new study permit before your old one expires, and it is generally a good idea to submit your application at least 30 days before your current permit expires.
As a foreign worker, you may extend your work permit in Canada. Citizenship and Immigration Canada recommends that the application for a work permit extension should be made at least 90 days before the expiration of your current work permit. Work permits may be renewed up to four total years of work in Canada.