http://www.washingtonpost.com/wp-dyn/articles/A4192-2004Jun24.html

Moore often resorts to speculative exaggeration that is either unfair or on point, again depending on your point of view. Early in the film he informs the audience that the president spent 42 percent of his tenure before 9/11 on vacation. This sets up a later image of a blank-looking Bush, just told that a second plane hit the New York towers, and Moore's rhetorical question: "Was he thinking he should have come to work more often?"

http://fahrenheit_fact.blogspot.com/2004/06/fahrenheit-fact-no-6-moore-distorts.html

how the "vacation days" were calculated:

It's obvious that these "vacation days" include weekends. (You can do the math: 250/x=42/100; x=595 days=1.63 years). Okay, 42% is a lot of vacation, but weekends account for 29% of our time. I'm sure that a lot of this "vacation" time is just Bush going to Camp David for the weekend. Can we really fault the President for going to Camp David on weekends? If you take out weekends, you get 42%-29%, or 13% of the time that Bush was on vacation. Okay, this is still a lot, although 13% looks a lot better than 42%. Over a year, 13% is about 6.76 weeks of the year--which is still much more than most of us. But we know that Bush's vacations are generally working vacations. For example, he has hosted visits from leaders like Putin, Fox, and many others there. This hardly seems like a real vacation. As Hitchens points out today, there are a lot of problems with Fahrenheit 9/11. It's pretty clear that Moore's "vacation time" allegation is one of them.

http://www.campusreportonline.net/main/printer_friendly.php?id=213

Moore blames the September 11th attacks on Bush by charging that in the wake of solid intelligence about terrorist plots the President just went fishing. Moore would have us believe that Bush vacationed more than he worked as the film claims that 42% of Bush's first 8 months as President were spent on vacation. What Moore fails to indicate is that the 42% figure, taken from a Washington Post story, includes: weekends, travel time, time at Camp David (a fully equipped Presidential headquarters), and time spent at his ranch where he planned a summit with Russian President Vladimir Putin and also met with Mexican President Vicente Fox. The 42% figure used in Moore's film was taken out of context; it was not vacation time but time spent out of the White House.