Yes you can make a cake 4 days in advance of the date you want to serve or eat the cake.
Just be sure that if you make a cake 4 days in advance that you keep the cake refrigerated during those 4 days.
If you leave the cake out at room temperature longer than 1 day then it could grow bacteria on it.
Another possibility is the cake could wind up getting mold on it which would make the cake bad as well.
But as long as you refrigerate the cake it's okay to make the cake 4 and even 5 days in advance.
However for the best tasting cake it's best to only make cakes 1 day in advance.
But you certainly can make cakes 4 days in advance and it will last 4 days in the refrigerator.
I would recommend waiting to ice the cake after you remove it from the refrigerator.