3. Set target dates from calculated

JIRA Portfolio can calculate and update Target Start and Target End dates and create a Gantt chart based on Assignee (Team Member), Weekly Hours, Estimate (Original Estimate minus hours logged), and the order of the tasks in the list. You will want to periodically have it calculate Target Start and Target End to get accurate projected end dates and Gantts. If you select at the Project level (as shown below) it will update all epics and tasks contained therein. You can also drill down and only calculate/update certain selected epics or tasks.

Please see the screen shot below which shows the steps to set target dates from calculated.