The SLA Date Field is a custom field that is used to search for issues against their deadline assigned in the SLA Metric Field. The SLA Date field's content depends on the SLA Metric field's content.
Adding the SLA Date field using the Add Custom Field button
Log in as a user with the JIRA Administrators global permission. Choose > Issues. Select Fields > Custom Fields to open the Custom Fields page. Tip: Use a Keyboard shortcut: g + g + start typing custom fields
Click the Add Custom Field button. Dialog displays the Standard choices for custom fields by default. Click on the Advanced option in the left navigation bar to search for SLA Date.
Select SLA Date by clicking on it and confirm your choice with the Next button
Editing the SLA Date field
Editing the SLA Date field allows you to change its Name (label), Description (Help text) and Search Template. More information is available at this link.
To edit a field:
Navigate to the Custom Fields page, locate the SLA Date field and choose >Edit:
The Name is the label that appears to the left of the custom field when it is displayed to a user.
The Description is the Help text that appears below the custom field when it is displayed in the Simple Search column.
Search Templates are responsible for indexing a custom field as well as making it searchable via Simple Search and Advanced Search (note that custom fields are not searchable via Quick Search). Every custom field type has a predefined search template, but you may select a different template using this procedure.