From airlineroute.net:

Air Canada during the month of November 2014 is temporary reducing long-haul operations from Vancouver, with overall frequency for each route being reduced from 7 to 6 weekly (Hong Kong 5 weekly). Planned operation reductions as follow.

Vancouver – Beijing 02NOV14 – 02DEC14 Service cancelled on Wednesdays from Vancouver, Thursdays from Beijing
Vancouver – Hong Kong 02NOV14 – 01DEC14 Service cancelled on Tuesdays/Thursdays from Vancouver, Wednesdays/Fridays from Hong Kong
Vancouver – London Heathrow 05NOV14 – 08DEC14 Service cancelled on Tuesdays from Vancouver, Wednesdays from London
Vancouver – Seoul Incheon 02NOV14 – 30NOV14 Service cancelled on Mondays from Vancouver, Tuesdays from Seoul
Vancouver – Shanghai Pu Dong 11NOV14 – 30NOV14 Service cancelled on Mondays from Vancouver, Tuesdays from Shanghai