Big bosses come in before 7 and leave around 6. Those that want to excel and have work to do mirror the same schedule. We have flex time, so some start their day as late as 9 and stay until 6 or later (with or without lunch). Lunch is not included in our 8 hour days. On average, throughout the year I work about 45 hours per week. Busier periods are in the 50s. We are expected to work as long as it takes to get the work done (if you want to get promoted). Granted, in the slow times sometimes, it is ok to have a "short" week.
Its risky business, but someone has to do it.