Sometimes the scheduled tasks is called like this. Here for example.
I’m not talking about scanning regularly the libraries. Of course it make sense to add files and manually scan them whenever you like! 
My point is: I prefer to decide when I want to wipe cache, generate thumbnails or whatever. It doesn’t make sense to wait until the tasks start or mess around with the times at “settings>scheduled tasks” If I want to start the tasks at 10:51 p.m. or so. Maybe I’ve added a lot of files or want to start it after I’ve finished watching a movie. 
Hope this make sense.
