Input (grade 13): In French "Belle de Jour" is an expression translating literally as "beauty of (the) day," as opposed to "femme de nuit" or "belle de nuit," women of the night (common references to prostitutes).
Output (grade 12): In French "Belle de Jour" means "beauty of (the) day," as opposed to "femme de nuit" or "belle de nuit," women of the night (common references to prostitutes).