Ontario High - School District Calendar - Chaffey Joint Union High - 2026-2027

This Chaffey Joint Union High instructional academic school calendar is extremely important as it keeps you informed of Ontario High grading periods, early dismissal dates, staff development days and holidays for the Ontario High calendar school year 2026-2027. As a parent and or student, you will find yourself needing this information on a regular basis, so please "like" and bookmark this page in a visible location within your favorite browser. The legend for this Chaffey Joint Union High 2026-2027 calendar is at the bottom of the page. If you are browsing on your PC there is another copy of the legend in the right hand column.