Based upon my experience with short sales - the bank will send a letter to the listing agent with their expected closing date. It usually is not a lot of time. In most cases its somewhere between 15-30 days. It will be in the form of a document style letter usually and it will give figures for all of the line items for what the bank has agreed upon, from seller concessions, taxes, title insurance, realtor fees. It usually shows up within a few days of the acceptance of all parties. Should you need to extend beyond the date that the bank has given - you may have two options: 1. to pay any additional fees that go beyond what the bank has agreed upon, i.e. taxes that accrue each additional day past close or 2. have the bank go through the approval process.
I am happy to help with any other questions you might have the Tampa area.