This statement is a symptom of a management anti-pattern. When a project hasn't been managed well from the start and turns out to be bloated and seemingly never-ending there is always a Project Manager around to 'save' the project by forcing the Developers to name a date when it will be finished.
neigh!…clip-clop, clip-clop, clip-clop…slam!!!
Hark, do I hear the sound of a stable door being slammed after the horse has bolted??!
This is like saying, "look, you've lost loads of money by betting on the horses, I want you to win, let's state a day when you're going to win big and it'll happen!". The Developers desperately want to finish the project, but new requirements keep being discovered, the end-user doesn't like the interface, stuff works in the way the Analyst said it should but not as the users wanted. Discounting the obvious solution of going back in time and doing it right in the first place, exactly what can a Project Manager do to turn the project around and bring it to completion?
I can't say that I have the answer…