I had reserved our tickets with Delta almost 10 months in advance, and they made several changes to our flights. Now, our tickets were award tickets, so I don't know if they had anything to do with the major changes that were made. The main one was that our return trip had a stop when the original tickets did not, and the final leg did not arrive until after 11:00. This set of changes was about the 3rd or 4th that had been made. When I noticed them, I called Delta and explained to them that we were travelling with small children, and I was able to change the return leg to a non-stop arriving at a time close to the original plan. I was not notified of any of the changes, and I had not been checking my itineraries as often as I should have. Watch yours carefully and calmly ask for any changes if necessary. Happy planning!