There are two ways to reschedule a participant: drag their slot in the study calendar, or use the Reschedule action in the participant list.
Via the participant list
Find the participant in your list (use Filter, then Name, if needed).
Click the dropdown next to their name and select Reschedule.
Pick the new time(s) in the panel that opens and send.
If the time you've agreed with the participant isn't in your calendar yet, add it there first, then reschedule them to it.
Via the calendar
Open your study's calendar and drag the participant's slot to the new time. They'll be notified the session has moved, and their status stays unchanged. It's still worth messaging them to confirm they can make the new time.
Getting an "unauthorised" error?
If you see an unauthorised or permission error when rescheduling or messaging, your account is on the Guest role, which can't message or manage participants. Ask an Admin on your team to upgrade your role, or have a Full Member do the reschedule. See How to invite people and change their permissions.
The participant can't make any time, or the slot is stuck
To free up a confirmed slot, cancel the participant from the participant list (dropdown next to their name, then Cancel). Don't delete the session from the calendar; that can leave the participant still holding the slot. If someone you cancelled still shows as Confirmed, cancel them via the participant list dropdown and then confirm someone else. Full playbook: How to tackle cancellations and participant no-shows.
Over-communicate. Any mid-study change can confuse participants. When you move a session, send a quick message so everyone is clear on when to attend.