So I’ve started making a two tier cake, it’s getting picked up on Saturday. It’s going to have a gold pearl border on each tier, I’ve done the bottom one, but I’m just thinking when should I do the top? I definitely need to stack it before I can put them on, but I don’t know how long in advance I can stack my cakes without them dipping or anything. Thanks in advance for any advice! 

As long as it is well doweled you could do it on Friday    Have you ever made a tiered cake?  Each upper tier should be on a cake board with the dowels in the tier under it   Then there will be no way for it to “dip or whatever” 

Ditto what kakeladi said!