For how long FISA takes to approve a wiretap, see Natl Review’s Byron York quoting the 9/11 Commission and other pretty good sources showing how long it takes, not for FISA to decide, but to ask it:
In 2002, when the president made his decision, there was widespread, bipartisan frustration with the slowness and inefficiency of the bureaucracy involved in seeking warrants from the special intelligence court, known as the FISA court. Even later, after the provisions of the Patriot Act had had time to take effect, there were still problems with the FISA court — problems examined by members of the September 11 Commission — and questions about whether the court can deal effectively with the fastest-changing cases in the war on terror.
Coleen Rowley, the FBI agent who ran up against a number roadblocks in her effort to secure a FISA warrant in the case of Zacarias Moussaoui, the al Qaeda operative who had taken flight training in preparation for the hijackings. Investigators wanted to study the contents of Moussaoui's laptop computer, but the FBI bureaucracy involved in applying for a FISA warrant was stifling, and there were real questions about whether investigators could meet the FISA court's probable-cause standard for granting a warrant. FBI agents became so frustrated that they considered flying Moussaoui to France, where his computer could be examined. But then the attacks came, and it was too late.
Which is what Bush wants not to happen again.