I mistakenly canceled 3 events on our calendar: https://www.blackjacktournaments.com/tournaments/friday-blackjack-tournament.2363/ June 9, 16 and 23. I can't see a way to re-instate them. I'm hoping that a moderator can do so. It would be nice to add that feature.
I remember developing some un-cancel options long ago, but maybe they were never completed. In this case, since it's only 3 weekly dates, it's not that important. If a single-time event is cancelled, it appears that you will need to re-enter it. I tried to test this on my local machine, but I need to upgrade my local copy of XenForo, and I no longer have access to that! Oh well. Sorry for the incomplete implementation.