Originally Posted by
rankourabu
With an overnight, no?
OP, welcome to dealing with Air Canada, best of luck.
No, the overnight was if the departure was still SJC.
No overnight is required for the most direct route out of SFO. The problem is the OP wants to fly an indirect route, leave no earlier than scheduled, and get in no later than scheduled.
AC doesn't want to route the OP on UA, because AC has their own flights that will work perfectly to get the OP from SFO to CDG at the original scheduled time.