Over the past year I've flown a lot on CO metal and a few times I've used the airport kiosk to make flight changes..ie confirm to an earlier flight. Each time I've noticed that at the CO kiosks you can not only change to an earlier flight..but also later flights including those departing the next day (for free with an elite fee waiver).

My question is.. if you change to a flight the next day, and then the next day comes..can you change it again to the following day? Or does the party end at that point?

Also, are these changes all possible online or only at the airport? I'm guessing online too.