That's not quite the range of the Phantom 3 Professional, which managed 2,500 feet without issue, but it's better than the 1,000 feet I got with the Phantom 3 Standard in open space and the 400 feet it managed in suburbia.
Medical specialists with a public voice like Dr. Oz should absolutely be encouraging people who are sleepy to sleep more. However, arbitrarily applying eight hours to everyone is actually harming people who simply need less sleep, or those who actually need more than eight hours.
calculate when to go to sleep to wake up refreshed. Calculate wake up time I'm going to sleep now; when should I wake up? Calculate bedtime When should I go to bed to wake up at a specific time? To wake up at go to sleep at If you go to sleep now, set the alarm clock to 11:15 pm. This will give you 7.5 hours of sleep. Alternatively you can go to sleepwake up at 0:45 am (6 h), 2:15 am (4.5 h) or 9:45 pm (9 h).