Ok lets talk about donut planets. This is a type of planet that has never been seen but is theoretically possible. If during the creation of a planet the colliding planetoids form a gravitational dance around each other in just the right way, they could coalesce into a toroid or donut shape instead of the usual sphere. Now this shape would be extremely delicate and since over the course of billions of years planets tend to get bombarded with asteroids and comets its not very likely (but not impossible) that one such shape would last long enough to grow into a planet.
BUT if one did this planets gravity would be weird to say the least. Picture something like our moon. Now instead of it going around our planet in a circle, picture it bobbing up and down through the hole in the middle of the planet. This is a theoretically possible orbital pattern for a donut planet. It could also orbit the donut in a figure 8 pattern. If a moon did go around the planet like our moon, then it wouldn't be a spherical orbit but more of a pair shaped orbit or rounded along the edges and a little widened in the middle where there's no matter and therefore no gravity to pull on it.
Now if you happened to live on the "hole" side of the donut planet then things would look similar to Halo. You'd actually see a vast (but rounded) landscape rising out of the horizon, soaring through the sky, arcing overhead, and then falling back into the horizon behind you. However if the donut planet is directly facing its sun at a horizontal angle, or an angle congruent with its rotation, then the inside of the hole would be an eternally dark frozen wasteland. But if that is not the case then it would be possible, depending on the angle of the donut relative to the sun to have two day times and two brief night times - with the sun rising and setting as well as eclipsing behind the opposite side of the donut ring.
As I said earlier donut planets, while possible, are highly unlikely. Their formation would be a 1 in a billion chance. But of course there's a lot more planets out in space than a billion. So maybe a few of them look like this.