Delta is notorious for doing this, and it's the reason why we will never fly with them again. The last time they pulled this on us, they changed our 4PM outbound flight, which we had specifically chosen in order to avoid having to take the kids out of school an extra day, and changed it to noon. They in turn changed our return flight so that we were leaving Orlando 6 hours earlier than we had planned. These were flights that we had carefully planned and chosen over other airlines because we wanted those specific times.
We've been flying Southwest ever since, and they have yet to change a flight on us.
We've been flying Southwest ever since, and they have yet to change a flight on us.