Personally, I would find it more difficult to spend the entire day on one task rather than splitting the day as you do in example 1.
What I do is listen to a podcast during my 1-hour commute to university, get to school early, and work during the morning and day on getting ahead with reports. In the afternoon I drive home listen to another audiobook or podcast, work some extra hours, and then focus on business.
Splitting up the day like this allows me to get ahead with work, and stay consistent each day with my tasks.
It would be best to experiment for yourself and determine what works best for you.