It's important to know what YOUR contract says about a deadline and contingencies. But as long as everyone's working together we can usually get things done without too many hiccups.
The reality is, you will close when the bank says you will close.
They can and do whatever they please...especially if you are working with Wells Fargo, Bank of America, Chase or Never Ever BAnk of Clearwater Fl.
Make sure you have proper protections in place.