You can increase your productive time per day significantly by actively influencing your sleeping habits. As a first step you avoid oversleeping because it makes you dizzy for a big part of the day.
As a second step you start to reduce your sleep by a few minutes every day. After a while you will find the right balance of sleep you really require. Since this very individual point is different for every person you can only find it through trial and error.
However, it is worth going through the pain since adapting your sleep patterns can easily gain 30 to 60 minutes per day. Think of what you could all do with this extra time over a year…