日付と時間
すぐ使えて、プライベートで無料
12時間制から24時間制への時刻変換機.
12時間制（AM/PM）と24時間制を相互に変換します。真夜中と正午も正しく処理します。
値を入力
入力すると結果が更新されます。
使用方法
よくある質問
Is 12:00 AM midnight or noon?
12:00 AM is midnight, which is 00:00 in 24-hour time. 12:00 PM is noon, which is 12:00. This is the single most common mistake in time conversion, and this converter handles both explicitly.
How do I convert PM time to 24-hour time?
For any hour from 1 PM to 11 PM, add 12: 3:00 PM becomes 15:00 and 11:59 PM becomes 23:59. The exception is 12 PM, which stays 12:00.
How do I convert AM time to 24-hour time?
Hours from 1 AM to 11 AM are unchanged, just zero-padded: 7:05 AM becomes 07:05. The exception is 12 AM, which becomes 00:00.
What is military time?
Military time is the 24-hour clock written without a colon, such as 1345 for 1:45 PM. Hours run from 0000 (midnight) to 2359, so no AM/PM marker is needed and there is no ambiguity.
Can I convert in the other direction?
Yes. Use the swap control to switch to 24-hour to 12-hour mode, then enter a time like 00:30 to get 12:30 AM or 13:45 to get 1:45 PM.