Got this from the Buffalo website: http://www.canadainternational.gc.ca/buffalo/imm/apply_pr_tr-demande_rp_rt.aspx?lang=eng
Temporary Residence
Applications for Temporary Residence from visitors, students or workers may be submitted to the visa office in person or by mail. A personal interview may be required. Some applicants may require a medical examination by a designated medical practitioner.
Applicationsfor Temporary Resident Visasmay be submitted in personbetween the hours of 8:00 and 11:00 am, Monday through Friday (public holidays excepted).
Because they are more complex, applications for study or work permits must be submitted before 10:00 am.
If the case is straightforward, we will make a decision on the same day as the application is presented.
If the applicant is not present, the application will be dealt with as if it were a mail-in application.
For security reasons, theRegional Program Centre does not allow the entry of recording or transmitting devices, including all types of cell phones, into the immigration waiting room or interview areas.
So it is possible to get the visa in a day even for work visas. But to be in Buffalo, the applicant must have a visa to the US or is from a country whose citizens do not need visas to enter the US