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.
The meeting ended at midnight.
This ticket becomes invalid as of midnight.
Means '12 o'clock' (midnight or noon) and is more ambiguous; 午前零時 explicitly specifies midnight.
Means 'noon' (12 p.m.), the opposite of 午前零時.
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.