I don't see why not. I mean, if there is still a spot available on another date, then they'd give it to you and you would also help someone else out by freeing up one spot.
I changed one of my interview dates, but you have to do it early to make sure the date you want isn't taken. Basically, it's all just dealing with the secretaries. So don't worry about the faculty members caring. They probably won't even know!