Lao Zhang told me in high season there were many many people at Vancouver Airport check in. So, please arrive in Vancouver airport
3 hours in advance 
of departure time. Note: If later or within one hour of your departure time, Air Canada or other airlines will NOT allow you to check in, then your E ticket may be invalid (non-changeable and non-refunndable especially for group fare tickets. Above information comes from
FlyGreatChina - Your Low fare specialist.
Call airlines for reconfirmation (in case airline change dates or cancel flight) . Airline Phone # is at
http://www.flygreatchina.com/travel/reconfirm.htm 
