I have some chickens in an uncovered big run during the day. There are places to hide (tall grass, barrels, etc) and shady places, as well as sheets hung/tied in strategic places to deter overhead predators and to provide shade.
I have some chickens in a smaller, uncovered run during the day. They have shade (tree or sheets) for protection.
I have some chickens that free range wherever they want to on the property. They tend to stick pretty close to the chickens in the runs and want to join them. (I don't let them join due to the female/male hormone ratio.)
I have some chickens that prefer to hang out in the front yard, right next to the house - they won't venture away from it!
I have some chickens that prefer to hang out on the deck in the back. They have to be encouraged to move along to green grass.
I open everything up just after first crow. Lol - NOT all the chickens appreciate that early call, but hey, if the roosters can crow and prevent me from sleeping in, then they should have to get up and get going too! Right?? If it's before dawn is finished, I usually stay with them for safety reasons. Dawn finishes up pretty quickly.
MOST of my chickens will go to their coop, their room, or their safe spot between 8-8:30 pm. I have one rooster (a sweetie!) that prefers to sleep right next to my back door on the social chair. I've got him on a bar chair now...(which is a little higher) and he will put himself to bed about 8:45 pm after everyone else is down for the night.
I do try to round up some of my chickens prior to 8 pm. My ducks like to leave their clubhouse about 6 pm and completely free range until about 7 pm. Then in for a bedtime snack and drink. Their room-mates, the Three Muskateers, are usually ready to come in about 7 -7:30 pm. They settle in pretty quickly.
Lol - now that I really think about it - it's my older guys that prefer the earlier bedtimes and my youngest are the ones that want to stay up later.

Chickens!
Regarding safety - do the best you can do. Accept that something may happen eventually. If you can be present when they are out, or check on them, do so. I walk and visit my chickens a few times a day. The over head predators see that. Sheets flapping in the wind also help deter predators. Hiding places help deter predators. All my animals know where to seek shelter. I rearrange thing sometimes. Keeps predators confused. All my animals know to run to me if there THEY feel danger/scared/concerned. And lastly, my animals will help each other in most cases. If one sounds an alarm, MOST of them will listen and look for the threat.
As others recommended, start them off with short outdoor time. If I raise the animals from babies, that's how I do it. For the animals I adopt, I usually give them a little more freedom with outdoor time in the beginning, if they have been free ranging prior to being rehomed.