I have already confirmed my PSs about a month prior to going because I discovered confusion about a date for a tour reservation quite by accident. (I was inquiring about something else and thought I might as well). The date was registered incorrectly somehow (miscommunication?). Well, I was grateful to have it work out and glad that I just happened to casually mention it and discover the discrepancy between my intention/plan and what they had me down for. Based on that, I decided to confirm my PSs and I will probably do it once more given that earlier goof.
KIS