Are you asking when it's done?
The last of us went gold on May 15th according to Cristophe's twitter account
It shipped Friday, so roughly a month from Gold master to store shelves.
Prior to that there would likely have been multiple weeks of internal testing, where little was changed outside of bug fixes, though those could include performance fixes.
So call it 8-12 weeks before the game ships, so if your aiming for launch in say Mid November you'd have to be done Mid to late Aug probably.
Of course, even then, bugs slip out: The Last of Us Autosave Bug
This stuff is HARD.