Issue Summary

In Confluence Team Calendar, events can be edited on an outdated date. If one user modifies the event date, it still allows another user to change the event date from the old date without warning them to refresh the page.

Steps to Reproduce

1. User A moves an event in the Team Calendar from today to next week.
2. User B has the calendar open in another browser tab (not refreshed) and still sees the event scheduled for today.
3. User B drags the event to tomorrow.
4. The event is now scheduled for tomorrow, overriding User A's change.

Expected Results

For collaborative tools, the expected robust behavior would be at least one of:

• Auto-refresh of events when they change, or

• A version check that blocks User B’s update and tells them “this event was modified; please refresh”.

Actual Results

There were no warning or message shown to the User before they submit the changes . System allows to change the Event from an which was already modified. 

• The calendar UI is not enforcing optimistic locking (no “this event has changed since you loaded it” check).

• There’s no refresh / conflict warning to User B; the backend simply accepts “last write wins”.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available