We offer a FREE 1/2 hour consultation to discuss your needs for college admissions counseling. Give us a call now at 952-449-5245 or drop us an email. Several colleges in the US use what is known as a trimester calendar for holding classes.In a trimester system, students have three semesters of approximately 10 weeks in each semester. During each of the semesters the student takes three classes.I know what you are thinking.e offer a FREE 1/2 hour consultation to discuss your needs for college admissions counseling. Give us a call now at 952-449-5245 or drop us an email. Several colleges in the US use what is known as a trimester calendar for holding classes.