Cal. Code Regs. tit. 16 § 331.7
Each school may elect to use the semester, trimester or four-quarter term system.
A school calendar shall designate the beginning and ending dates of terms or semesters, the vacation periods and legal holidays observed, and the dates for semester and final examinations. The recitation or lecture period shall be not less than 50 minutes in length. The school may operate on a five or six-day week or any combination thereof, but the total number of hours of instruction shall be not less than 30 hours nor more than 35 hours per week. The total number of hours provided for each complete student's course, leading to the degree of Doctor of Chiropractic, shall be not less than 4,400 hours distributed over four academic years of nine months each.
Cal. Code Regs. Tit. 16, § 331.7