I have a reservation on AA whose first segment is more than 24 hours away. However I am unable to change the date of one segment online. That button does not seem to be selectable.

I vaguely remember a schedule change. I have a feeling this problem started after that. I noticed the same on a past reservation and on another in which I made one change.

So I'm wondering if there are any restrictions on date changes after an invol schedule change or if there is a limit of one date change.