>>11589779*sigh* Well, I'll infer something from this post: Seeing as moving to another planet that would require terraforming, or possibly even the entire construction of a functioning ecosystem and climate is dumb, and a waste of time, in that it makes more sense to just build a bespoke rotating human habitat in orbit and use the planet as a resource mine. I'm guessing you are implying that the planet is already habitable, in which case, it probably has some form of simple biosphere, like early Earth. In which case, as viruses appeared on Earth billions of years ago, when other forms of life where still very simplistic, it is likely that the planet already has its own endemic viruses.
So, to answer your question is brief: Zero time, as the habitable planet would probably already have viruses of its own.
