vBulletin Manual - Moderate Events

In addition to moderating threads, posts, and attachments, you may also moderate new calendar events. To do this, go to Moderation > Moderate Events.

Posted By – the user that posted this event. This is not editable.
Calendar – the calendar this event was posted to. This is not editable.
Subject – the title of the event.
Date – the date(s) which the event is active for. This is not editable.
Event – the body of the event.
Action – like the other moderation sections, you may Validate (display), Delete, or Ignore (do nothing to) each event in the queue.