Are they going to be going out with other birds that are older and have learned to come and go?
I think they are kind of young to let go all day but you could start by letting them out for about 30minutes before the sun goes down and then herd them back inside. Just work your way up over over the next week to longer and longer time.
I had them. They are the nuttiest things!! I got rid of them because I couldn't deal with the NOISE during post chemo weeks. My husband called them the Air Raid Sirens!