The article makes a good case for why you might not have a good idea for what it means for my friend on the other side of the country to wake up an 9. In the United States, for example, there are states that opt out of Daylight Savings Time. A Google search could tell me what they are but I haven't memorized them. And even at that, if my friend was making a point about how long the sun had been up (or down), I would to mentally translate after checking a sunrise/sunset calculator.
When I need to synchronize with someone else, time zones get in the way. When I need to describe an experience relative to where I am, I might want to refer a time calibrated to exact my coordinates on the Earth. That was hard in the 1800's but would be easy today now that everyone carries a GPS receiver in their pocket. The same for reporting time relative to sunrise.