Issue Summary

Users are unable to load calendar events in Confluence Cloud when their account timezone is set to Egypt. The UI displays an error “unable to load events of <calendar-name>” along with a hash and trace value, and the corresponding API call fails with a 500 Internal Server Error.

Steps to Reproduce

1. Go to Atlassian account preferences:
   https://id.atlassian.com/manage-profile/account-preferences
2. Set the timezone to Egypt
3. Now Attempt to load/view calendar events
4. Observe the error on the UI
5. Capture HAR logs and check the failing request:

   /wiki/rest/calendar-services/1.0/calendar/events.json?subCalendarId=xxxxxxxxx 

   Note: This might not happen for every calendar

Expected Results

• Calendar events should load successfully regardless of the user’s timezone setting
• API request should return a 200 OK response with event data

Actual Results

• UI displays error: “unable to load events of <calendar-name>” with hash and trace ID
• HAR logs show 500 Internal Server Error for the calendar events API
• Issue consistently occurs when timezone is set to Egypt

Workaround

• Change the timezone in account preferences to an alternative timezone with the same offset (e.g., GMT+2)
• After updating the timezone, calendar events load as expected