MIT’s policy on academics and student absences for religious observances allows students to be absent from classes or to be excused from academic work or exams to observe a religious obligation or holiday if they coincide. Religious accommodations are offered in addition to other policies which the instructor of the subject has for excused absences or dropping the lowest grades.
For example, if all students are allowed to drop their three lowest grades, a student would not be expected to use one of these three drops for a quiz or classwork that they missed due to a religious observance. An appropriate accommodation would be to allow the student to make up the missed work after the holiday.