Teamup provides event edit history: who created an event and when, as well as who last modified the event and when.
1. The event: See the (exact) time and date that an event was created or last modified by hovering over the time stamp at the bottom of the event editor. A pop-up will appear with the precise date and time:
2. The Table View: You can sort events by creation date and/or last modified date.
Set the 'Created' and 'Updated' column to show (via the Show/Hide columns option) and sort the list of events accordingly:
3. Change notifications: Set up your calendar to send out email Notifications when changes are made to the calendar. The notification email lists the link name or the user that made the change.