The "missing" 5 days are due probably to a combination of factors, one of them being that the flight does not operate daily, another that the schedule probably does not get loaded in lan.com at precisely midnight of the 365th day, etc. I suggest you monitor lan.com for the next few days and try to do dummy bookings one year out. That will give you a feeling for exactly what to expect when you call LA. The other thing you should do, of course, is call LAN and get their take on things.