With this feature, you can share your schedule and plans with your customers. There is one calendar in the Service Management Help Center. It includes the service-desk issues:
where the current customer is a Reporter,
where the current customer is a Request Participant,
where the current customer is in Organization, with which the issue is shared.
Let your customers know the planned timeframes for their requests!
The fields associated with start and finish must be specified for the issue to be displayed on the Calendar. Check which fields are required in Jira Settings → Calendar → DateTime Custom Fields. Ensure that the fields selected there are accessible for your agents in issues.
Set the fields to be displayed on the issue glance and on the issue preview (Jira Settings → Calendar → Service Desk). Here you can also set the JQL-based color rules for issue displaying.