I want to build a world with inhabitants living in a constant twilight zone, although the planet itself should still be rotating and not be tidally locked with the sun. Optimally I'd want it to be a constant sunrise/sunset or civil twilight with the sun still visible.
In my original idea, the inhabitants would not be measuring time in morning, noon, etc. but in compass directions depending on where in the sky they currently see the sun.
Now thinking about how such a world could exist, my assumption would be that it would have to be an earth-like planet without axial tilt (obliquity) and the inhabitants living on either pole. But then compasses wouldn't work, right? Does anyone have other ideas on how to construct such a world?
If not, how would the inhabitants tell time then?
I would also like the story to take place in a climate warmer than earth-like poles. Let's say around 15-20 celsius / 60-70 Fahrenheit mean temperature. If other areas of the planet become uninhabitable, so be it :) What parameter would have to change to achieve that?
The scale of this twilight-zone should be around 300 miles / 500 km wide. Would the scale of the planet have to be adjusted? By how much?
What else would change on the planet? Would there still be seasons? What would the other areas of the world look like?