Covering a cake with fondant icing- will it last longer?

[yummypickledeggs]

I want to bake a cake that will be eaten on Friday/ Saturday and beyond.

If I bake it today would or tomorrow would it stay as fresh as baking on Friday - IF I cover it in fondant icing?

It's a simple sponge with buttercream filling then fondant over the top and sides.

I'm no expert but I think so, if it's well sealed with fondant and in an airtight box

Yes - but don't put it in an airtight box, that makes fondant sweat.