AC845 FRAYYC and AC875 FRAYUL have traded slots for the winter. It is very likely that this will continue into next summer.
The early departure from FRA to YYC allows better connections to Western Canada, particularly for the ski market. It also allows tighter connections in FRA from the Middle East and Indian subcontinent. This will also be the earliest international arrival into YYC from Europe.
Also, the A330 will fly this route for the full season.
Conversely, this benefits FRAYUL by offering later connections from within Europe to YUL. This is important in the more competitive YUL market.
Hopefully, you will learn to love this new timing.