* Grade level: Lower school (elementary) may have shorter days than upper school (high school).
* School policies: Some schools prioritize longer days with fewer extracurricular conflicts, while others have shorter days with more flexibility for activities.
* Specific school traditions: Each school develops its own rhythm and schedule.
To find the specific hours of a particular Boston prep school, you need to check that school's website. Look for a section on "Academics," "Calendar," "Daily Schedule," or "School Day."