Changing the start date of tasks

Hi, I'm managing a project in my team, but the developer didn't change the status of the task she is working (to set "In Progress") in order to have a start date for the task, even with her submitting hours spent on the task.

Because of that, the start date is completely wrong, I want to know if it is possible to set the start date manually ? I really think it is incorrect in RTC.

Thanks!
Rodrigo Gonalves