Define sunset.
When you are in the woods with ridges behind you and can't see the horizon, how do you know when the sun sets where you are? When the sky is clouded, how do you know when the sun sets? I hunt until it is too dark to positively identify a target and accurately shoot it. This changes on a daily basis with weather conditions.
I have been trapped in a stand until close to 8 pm because of deer under me that I didn't want to spook and educate. That doesn't count does it?