I was reading some more over at ticketcombat.com. He recommends at least 15 days (if faxed):
"Your disclosure request should include a reasonable return date (diary date) of seven days for Canada Post to deliver it (if you don't fax it) plus 15 days for the prosecutor to gather the information. You should request disclosure well in advance of your trial so that you have enough time to review it and also enough time to request further follow up information."
http://ticketcombat.com/step4/disclosurehow.phpBased on this, 4 weeks in advance (as my buddy did) should be adequate!!