That I don't know. I guess I could look it up, but I'm too lazy to. For me, the difference between moveable and not moveable days is next to nil.

Scheduling doesn't move a day unless they have a pressing, immediate need. They are not strategy-minded whatsoever. They won't look a week ahead of time and say "my, we need an extra FO on the 20th, let's screw FO Nola." Their job is just a series of small fires they have to put out before they can go home and leave the chaos to the next guy. By the time they figure out they need to screw you, you should already be home with the phone turned off and a beer in your hand.

What I'm trying to say is (and chime in here if your mileage has varied), the times that Scheduling both need to move a day on you and can contractually alert you in time to make it happen are so rare as to be shocking when it happens.

edit: I have had Scheduling move a moveable to satisfy the 7 day rule. I think they can do this one time per month (if it makes a 'standalone' day off). Sometimes they just give you an extra day off, but that has become less common.