When you hire a freelancer, work with him, explain your project to him, understand how much time he has, and accordingly then set targets.
Human beings have a tendency to procrastinate. If you say whenever, it may never materialize. So, give people a target date; even if you don’t need it tomorrow.
People deliver on deadlines, if you don’t give people deadlines, they will deliver poor results and you will regret it.Give freelancers a three or four day lead time but give them a ‘Hey, can you get this done in three, four days?’ if that is what you think it will take.
So give people a target date.