Originally Posted by
Ragnarok
You need T class for Confirmed Change. But the context of Same Day is a mood point because if the new flight you want has T Class available, you can request the change even before T-24. It's just the same as changing an award ticket in general, you are not subjected to any of the SDFC rules but rather is subjected to award availability. No Change Fee for AA Award changes now.
If T space is available, yes, the SDFC rules are moot.
But what if T space is not available? A regular change can't happen, but what about SDFC?