I don't really know how to explain this but In my world the sun just turned into a map. 

Additional information from MC-225726:
The moon was going down, and I looked at the rising sun. It looked like a skin file, and it was the texture file for a pillager. I did not have any texture packs, mods, shaders, or any such things loaded. It was vanilla Minecraft. In a different world the sun looked like a map. It might have something to do with the fact that I was in a raid, when the sun looked like a pillager. Also When the sun looked like a map the map looked like the sun. The pillagers were also solid black, though the crossbows showed up. When I pressed F3+T to reload resource packs it went back to normal.