CIC (Citizenship and Immigration Canada), nobody know where in Canada. But this is the not job of visa office. visa office just write on in the own systems. each visa office have own systems. all systems connected to CIC , and CIC update the DB of www.cic.gc.ca.
On the cic website they have said that they update on tuesdays but at New Delhi CHC I have seen updates on Wed and Thu as well. So believe CIC is doing it every Tuesday and CHC generally on Tuesday but otherwise also
All VO systems connected with CIC DB centralized. this is the normal IT thinking as I belive. Don't think more since last couple of months people geting updated e-case everyday (some people already discussed before like Wayne he got medical on anotherday not on tuesday)