Jira allows creation of planned start and end dates for every issue type. Regardless of how you structure your issue tree, you can apply planned starts and ends to each level to track against completion targets.
Allstacks supports the following conventions across Jira Classic and Jira Next-gen
End dates:
Built-in ‘Due Date’ field
Any custom field containing ‘planned end’, ‘end date’, or ‘due date’ (case insensitive)
Start dates:
Built-in ‘Start Date’ field
Any custom field containing ‘start date’ or ‘planned start’ (case insensitive)