4 months, September to December. So I am a visiting professor. Think of exchange program but for professors. The way this works is you are an employee of an academic institution back home. You get paid salary there and you are sent to Canada to engage in various activities such as teaching classes, participate in research, create programs etc. Some of activates are paid activities by Canadian institute such as teaching classes. Some would involve other forms of reimbursements, renumeration. Some activities are going to be unpaid as well. So you get paid full time salary back home from your institute in your local currency plus the salary for the paid work you did in Canada in CAD.
For me I took classes for 4 months September to December, which was paid work and I got T4. Since then I am working on research which is unpaid here in Canada. I will be returning back to my institute and country on August. It was 40 hours of work per week for 4 months