[Sloth]

Hello, I am thinking about getting a cockatiel and have two questions regarding sleep. I am aware that most birds including Cockatiels need around 12 hours of sleep every day. First of all, is it possible to leave the cage covered for less (9-10) hours in order to have more time with the bird in the morning, or is it better to leave their cage covered for 12 hours straight? Secondly, will a cockatiel be able to sleep if there are people awake and the lights are on (With their cage covered)? What could I do to give my parrot a good nights sleep when I am still awake? Thank you!