noun
midnight; 12 a.m.
Formal or precise term for midnight, often used in schedules, official documents, or when clarity is needed. In casual speech, 夜中の12時 or 0時 is more common.
会議は午前零時に終了した。
The meeting ended at midnight.
この切符は午前零時をもって無効となります。
This ticket becomes invalid as of midnight.
Compound of 午前 (a.m.) and 零時 (zero hour, i.e., 12 o'clock). The use of 零 (zero) reflects the 24-hour clock convention where midnight is 0:00.