Weird - perhaps some issue with other sources picking up a 24+ delay?

Two options - try get to the airport ASAP and get rebooked. There are limited seats direct on Air Canada at 6.30pm, via Frankfurt at 4.15pm on Lufthansa or via Seattle on Delta at 5.09pm

Otherwise if you are in a hotel and the cost is reasonable (around £200 seems to be the figure I've seen on before ) and you are able to then extend your stay and forward the bill for accomodation and reasonable food and drink to BA and fly on the revised flight tomorrow. Otherwise at the airport they will be able to put you up