Let's say that society decides that 8 am is appropriate to start business. Most businesses open around that time. Let's say to provide a reference, that 8am is

Let's say that society decides that 8 am is appropriate to start business. Most businesses open around that time. Let's say to provide a reference, that 8am is 1 hour after sunrise on June 10. By pushing the time forward, 8am is now when the sunrises on June 10. You have effectively made everyone start the day at sunrise instead of 1 hour after sunrise. This is definitely a morning-person thing. People who are functional earlier benefit over those who aren't.