Of my 28 proton radiation treatments (during April-May 2021), all were scheduled a week in advance.
> the 1st 3 weeks were all at 2:40PM
> the last 2 weeks were all at 2:00PM

(That helped me schedule my life around the treatments.)

Immediately after each Friday session, I would meet with the RO to discuss my status and to plan out the next week’s sessions.

2 of the sessions had to be rescheduled:
> once due to a machine malfunction;
> the other due to a re-scheduling that I needed to make.

For each session, they were always on time; never more than a couple of minutes wait. Plus, they gave me a temporary handicapped permit so that I could park right next to the proton facility, rather than having to walk from the main parking lot.

I’m a very process-driven person. By having (what I considered to be) a structured process, made it a good experience for me.