All of the University of California schools (except for Berkeley and Merced) are on the quarter system. I really liked the quarter system. It really felt like professors couldn't waste your time with busy work activities. Everything was very focused.

UC Berkeley switched from quarters to semesters in 1983 ( https://dailybruin.com/2018/06/08/the-quad-the-long-convolut... ). At the time I thought it was because spring quarter is over later than spring semester (because of Christmas and New Year) and students from quarter-schools had a hard time finding summer jobs because the semester students had already taken all the jobs.

I went to school at a Canadian university with a 4 month summer break at the end of the winter semester: just as temperatures were warming up, it would last long enough to earn tuition, rent and food for the following school year.

Same for Delft University of Technology, Netherlands: https://www.tudelft.nl/en/student/education/academic-calenda...