ことになっている

This grammar expresses that something has been decided or arranged by someone else, or that a situation is officially planned or expected to happen. It emphasizes an external arrangement, rule, or agreement rather than the speaker’s personal intention. It is common in formal contexts, announcements, or when reporting plans and outcomes. Use it when you want to convey that something is scheduled or understood to be the case due to prior decision or circumstance, not because you decided it yourself.