Agree with JerryFF and Droneklax. Had this happen to be once. Bought a ticket in March to SYD for travel in June. UA did a schedule change sometime in May. Now the question is, what can't they published the correct schedule to begin with to account for the time change???

As for padding, UA has been doing that (at least domestically). Padding is not shameless. It's accounting for the delays that are occurring quite frequently. If someone doesn't like the fact that it takes UA 1 hour and 15 minutes to get from A to B while a competitor takes only 1 hour for the same route, they can always travel on the other guy.