I hava  a cake order  for today at 6 pm  is now 12 .40 pm i just took out my cake out of the freezer so still frozen i never froze my cake ,how long will thake for the cake to thaw (is a 12' cake 3' high allready cover in icing ) i need to cover it whit fondant can i do it if the cake is still frozen ,please help me.

It will probably take that long to fully defrost so unfortunately your only option is to cover it with the fondant while it is still partially frozen. You will probably get some condensation forming on your fondant, but if you don't touch it while it's damp it will be fine - if you do touch it you will get fingerprints on it. The condensation will evaporate after a while. I just hope your customer is not going to want to cut the cake at 6.30pm as it could still be frozen then...
 

Thank you