I tried to utilize the timeline bar in a project but I cannot move it:

All of my timeline bars are part of an Epic, and all of them are added in sprints. What I want to do is for our sprints, I should be able to adjust the bar to reflect the dates (For example, development takes place on the first 8 days, then testing is on the 9th and 10th day, etc.)
How do I achieve this?