The class was scheduled to take the final next week. I wanted to take the test this week, because there's some place I was planning to be on the day of the final. My teacher said that doesn't count as an extenuating circumstance, and that his dean wouldn't like it. His dean isn't even administering the exam, so why would she even care?
Allowing students to take finals at other than the scheduled time could cause the following problems:
Complaints from other students (in other courses under other professors) that they weren't allowed to take their final exam at a nonstandard time. "My friend Johnny got to take Professor Smith's final early, why can't I take Prof Jones's final early."
If the same final exam is used for all students, then students who take the exam early can leak information about the questions to other students.
To avoid the problem in point 2, we often give a different final exam to students who must take the exam at a non-standard time. However, this can lead to complaints that the alternate exam is unfair. At the very least, it means extra work for the professor in writing the exam.
There are certainly circumstances where a student can't take a final exam at the scheduled time. For example, a student in one of my classes is ill, so we've arranged for a makeup final exam to be given in January at the start of the spring semester.
If there is a scheduled time when exams are given, the dean is often the person who receives complaints about exams that are given at the wrong time (e.g. if the professor unilaterally moves the exam). The dean cares because he or she has to deal with the complaints!
To keep things organized, the dean may have told the faculty (perhaps through their department chairs) only to reschedule exams if there are extenuating circumstances. That would not be an unreasonable or surprising request, in my experience.
The professor might (depending on the institution, their tenure status, and their own sense of agency) be able to move your exam anyway. But the answer you received should be viewed as a polite "no".
Personally, I am only sometimes able to move the exams in that way. It depends, for me, on whether I have the exam written, what day and time the student wants to take the exam, how many students I anticipate will want an alternate time, etc. Of course, if there is a serious circumstance I will schedule a make up. But just wanting to be somewhere else is not much of an extenuating circumstance - taking the final is an expected part of taking the class.
"Someplace where I was planning to be" doesn't tell the full story. By itself, that's a reason for denying a request for a different test time.
"Someplace" (at a particular time) is a lot more excusable for an emergency. If there is an illness or potential death in the family, and you need to get there before, say, one of your parents die, or for a scheduled funeral, that would be an adequate reason for rescheduling your test. So might a (legal) "court" date; possibly even another "court date" at the invitation, of say, Queen Elizabeth II.
But barring a "good reason," professors and deans are supposed to deny requests for rescheduling a test.
Here is a perspective people don't usually consider...accreditation. Each student is required to meet a certain amount of instructional hours per class. The accreditation committee sets the required hours and audits school records to make sure these requirements are being met.
If a student takes the final early, it implies they are going to miss a class. By allowing this, the teacher has tacitly agreed to violate the accreditation requirements of the class.
I now have 2 students who want to reschedule their final exams - both for valid reasons, but both in reasonably high level courses - calc 2 and a programming class. The final for Calc 2 requires significant preparation time, and time setting the rubric. The programming exam is easier to write but harder to grade when there is just one person taking it. Both require an addition of about 8 hours (each) to write, proctor and grade these finals. I don't want to stand in the way of my students who have excellent opportunities - but I have a policy in place that requires exams to be taken at exam time - barring extreme (i.e. hospitalized emergencies). Part of the problem is the schedule of the college I teach at - spring semester runs into June. The other problem is guilt - other professors are doing it so I should to... peer pressure maybe. There should be one clear campus wide policy requiring students to take the final on the day scheduled. I shouldn't be spending any time worrying about this. :-/