grumbleradded a comment a year ago
Why have you not been to school today?
Почему ты не был в школе сегодня
Почему ты не был в школе сегодня?
EditedWhy weren't you in school today?
Why have you not been to school today?
HAVE YOU NOT BEEN is a present phrase, so it can only be said during school hours. If we're to assume that this question is asked after the school day has ended, then only the simple past makes sense.