St. Peters Basilica—what time does it open in the morning?

I have been looking on their website and cannot find the hours of opening and closing.
We want to be there as early as possible.
In one place it says the dome access, I think, opens at 7:30 in the summer. We will be there in May so I don’t know if that applies to May or not. Does anyone know where I can read about opening hours online?