I'm assuming you are referring to a fictional character named Margie, who appears in the short story "The Fun They Had" by Isaac Asimov. In the story, Margie is a young girl who lives in a future where schools are mechanized and students learn at home through machines.
In the story, Margie does have regular days and hours of school, but it is not because she attends a traditional school with teachers and classrooms. Instead, Margie learns from a machine in her home, which has a set schedule for when she is supposed to learn different subjects. The machine is programmed to provide lessons at regular intervals and to test Margie's knowledge periodically.
The reason for this regular schedule is likely because the education system in Margie's world is designed to be efficient and standardized. By providing a consistent learning experience for all students, the system can ensure that everyone receives the same education and that they are all prepared to enter the workforce. Additionally, having a regular schedule for learning helps students develop good study habits and routines, which can be beneficial for their academic success.