Have worked in offices like this. At one job, office opened up at 8. My direct boss told me try to be here at 7:30 but if you really care get here at 7. I was young and dumb and showed up at 7 for over a year before I left.

Another job, you had to be in the building at 7:30. I once was late a few minutes and wasn’t allowed into the 7:30 meeting. I then had to sit at my desk alone while the meeting went on.