Symptom
Error message "You did not enter a valid date" displays when submitting a JIRA issue.
Cause
Your server may be configured to use a custom date format or a non English locale.
Resolution
You can change the date format settings in the 'Advanced Configuration' section under the 'Additional Settings' section of the repository properties (Window -> Show View -> Task Repositories) to match your server configuration.
Screenshot: JIRA Date Format Settings
Overview
Content Tools
Apps