What Detention Is For
We know that pupils who transgress the academic code of conduct may be subject to school detention as a form of discipline. For a predetermined period, typically after class, students sit in a room under the close observation of an instructor.
The purpose of detention is to discourage students from engaging in the same behavior that got them into it. Any conduct that a school official finds to be detrimental to learning may be cause for detention. Being late to school is one of them.