You're not confused, oly.
We are confusing!
A lot of us change early because, well, we just like to prolong the fun!
Sometimes turnees may change in the middle of the night when we're not around to party with them and let them enjoy their special day.
Traditionally, the day of the turning is where the avi change started. It just kinda grew into the Eve of the Turning and then the Day before the Turning...
It's whatever makes you happy.
Pad's turning time is early in the morning tomorrow - either 0825 or 0925 is what I've read. A lot of people who participate will miss the actual festivities: by being either at work, or it being too early (especially for West Coasters) - so we are honoring him all the day and eve before.