Light building question

Hello,
I notice when I build lighting, it builds the entire world. So say I added some planets once that 1hour finishes (because the map with terrain is 65×65 then the highest terrain setting is 255×255) the lighting is updated, but then I add a rock, and the lighting builds the entire world again so I have to wait another hour just for adding a rock because its rebuilding the entire world lighting. Is there a way to have the lighting build just for the object you added. Like update it to the current lighting?

No, it’s not possible!

you don’t need to build every time you add something.
If you absolutely need to see how the shadows look try using dynamic lighting as you build your level then switch back to static when you need to build lighting and see the bake results.