How to switch default home launcher at macrodroid

I use several home launcher apps. At my school, i use system launcher.And at my home or any other cases,i use nova launcher. And,ther are secret apps that i don't want to show my friend in nova home. So,i want to swich default launchers automatically at a certain time. I think i can use macrodroid.But I'don know how. Are there any shortcut to swich default launcher in app? (it's not good idea to touch the app icon to swich to go to nova or another home) (I don't want to root if possible)--edited