I do know of one case in which the person applied in late July but still received the visa on time in early September (and had their medical tests done in August). This happened last year, though. I think the CHC tries to keep the start of your program in mind and probably speeds things up in July/August. So even if you applied in July, it might be possible to get everything done in time, but you may want to contact your uni and let them know you could be a couple of weeks late.