I put my 6-8 week old chicks out in their coop three days ago. The first day I left them inside, though I opened up the cleaning doors and talked to them, like I did when they were in the brooder. By day 2, they seemed comfortable and settled, so I opened the pop door to the run for some supervised outside time. Only a couple actually came out and only briefly. 
Yesterday, I opened the door in the morning and left it that way all day except for a couple of times when I had to head into town (more my nervousness than theirs, lol). They still only come out when I am in the run (a couple still haven't left the coop at all) and quickly go back in when they feel uncertain, which is often for most of them still. Each time out they seem to get a little bit braver. If I'm not there with them though, they all prefer to hang out in the coop where they feel safe, even though the door is open for them to go out.
So, in my case, I kept them contained for less than 24 hours, just until they seemed comfortable and at ease inside. That is working well for me, but I am learning that every chicken and every flock is a bit different. (NOTE: Without a safe, enclosed run, I most likely would have waited several days before letting them come out rather than risking them getting scared and running off.) 
I suggest watching them for cues and adjusting your tactics accordingly. Good luck!