Now that the weather is nice. Its about 70-75 here, I put my chicks outside while I clean their brooder out. They are only about 9 days old. I will let them play and peck at the ground for as long as they want if I have the time. As long as they are pecking and exploring instead of huddled or peeping, and as long as I'm out there, I let them have recess for anywhere between 20 min to 2 hours. I do yardwork and never leave them unsupervised though. They will let you know if they don't want to be out there and you will be able to tell if they enjoy it. If they were with their momma they would be allowed access to the outside from day 1.