Hardly anyone is purely one or the other, which is why this argument never ends. You have had 6am weeks where the quiet felt like a gift, and you have had midnight stretches where the work finally clicked at eleven and kept going. So when someone asks which one you are, you stall, because both answers have been true this year. The wheel picks a side and lets you get on with the conversation.
Early bird usually means the hours before anyone needs anything from you: a still kitchen, an inbox nobody has touched, and a head that has not been talked to yet. Night owl usually means the opposite trade, the day's obligations paid off first and ideas that only loosen up once the house goes quiet. Neither one is discipline and neither one is laziness. They are two different kinds of quiet.
This wheel has exactly two slices and no opinion about which is better. Use it as an icebreaker where you spin first and then defend whatever you land on, as a fair way to split a class into two debate sides, or as a nudge when you cannot decide where today's hardest task goes. It will not diagnose your chronotype and it will not fix your sleep. It just ends the stalling with an even draw.