Thank you for your message.
In Joomla, the "Created Date" field is not available in the frontend article editor by default. This field is handled internally by the system and is not intended to be manually set via the frontend. Only "Start Publishing" and "Finish Publishing" dates are exposed for scheduling purposes.
Since you're using the "Created Date" as the event date, we recommend using a Custom Field instead. You can create a date-type custom field (e.g., "Event Date") and assign it to your articles or a specific category. This field will appear in the frontend editor and can be used reliably for your event date.
Best regards