Final exams: What is the most common protocol for scheduling? At my college this semester, just a few weeks before spring final exams, the administration decided to entirely throw out the prior process for scheduling final exams (which has been in use for at least two decades, I think). Whereas scheduling, duplication, and collection of final exams was formerly centralized, basically it all immediately regressed to being each department and instructor's responsibility. Suddenly there are many (hundreds) of instructors and students with conflicts (two courses at same time in different rooms) and no defined process for solving them. Various instructors and departments are arbitrarily shifting finals to other days, times, rooms, etc. (which seems likely to cause more conflicts). 

Our day class meetings are traditionally one-hour apiece, and our final exams have always been two-hour blocks. One of the people partially involved with the recent decision has claimed that these problems would be best solved by having a few days where departments with large common finals hold theirs, then followed by standard class meetings for a week in which the majority of instructors can do whatever they want; possibly extend the meeting to two hours, or split the final into two separate days, etc. The final claim is that this latter protocol is "how it’s done in almost every other college in America".

In my limited experience, it's hard to see how this proposed process (keep standard class meetings and let instructors work out final exam times on their own) is common or feasible. Is it truly how it's done in almost all U.S. colleges? If not, what is the most common protocol? Any references or evidence to support claims one way or the other?
In the two major US state universities that I have either been a student or taught in, the process was roughly the same:

Final exam times were based on the first day of the week course time for the main course meeting, typically a 'lecture' section. Every course that started at 9am on a Monday had the same final exam time. Every course that started at 11am on a Tuesday had the same final exam time. All these decisions were made centrally.

The exam times were mostly unrelated to the actual course times, since the final exam slots were longer than the actual class meetings, but it ensured that no one had overlapping final times because no students would have two courses that met at the same time. The exception was courses that were specifically night courses, which also had night finals, with the assumption that some proportion of the students in those courses were not full-time students and may have had other daytime responsibilities.

I believe there were procedures to allow for simultaneous finals for courses with multiple sections, but I am less familiar with how those processes worked; I believe the centralized time was chosen and then arrangements were made for the small number of students for which there was a conflict.

There were also processes for students who ended up with >2 finals in the same day to make alternative arrangements, but again, these circumstances happened rarely, especially because not ever course actually utilized their final exam slot as anything but a due date for a paper/project/etc.