How long does it take an offer to be accepted?

[Allison Jones]

We put an offer in on a quadplex in foreclosure that was being advertised as a single family home due to falling out of the grandfather clause of non conforming use. The property was on the market for months.  We found a loop home with our planning department and put a full price offer on the property on Thursday.  How long should it take to get the accepted offer or counter offer from the bank?