look for the char played by Sutherland during the first meeting at Getmo. he has a very short, Marine haircut. What amounts to several days later, when he is in court he has at least a month or so of hair growth.
The meeting at getmo occured almost a month before the trail. Although there is no actuall time frame in the movie that I can remember, the amound of pre-trail stuff completed would take almost a month!
There was about a month. At the time of the meeting was before Santiago died. When they were in court to pled Guility or Not Guilty, the judge then said that trial would be in 3 weeks.