the information on the call sheet is incorrect if an attendee joins and leave immediately.
register a new attendee
start the session
join the session and wait a couple seconds
close the browser window.
Arrived at session and departed from session list 5:00:00 PM even though the event started at 10:55 am.
The left before end of session time is below
left 26597825 minutes before end of session
I believe this is probably because the attendee joined and left in less that 60 seconds.