UCSF and Dartmouth seem to have the same revisit weekend May 2-3. I'm not entirely sure though, since UCSF could have a separate MSTP-only revisit.
I don't like late revisits, by that time most schools are already pressuring you to make up your mind, and schools generally hate late withdrawals, so I have no idea why they would still procrastinate in admission, arrange last minute revisits, and cause mutual hatred...