If you are converting between the 24-hour and 12-hour clock, use this quick reference: 24-Hour Format 12-Hour (AM/PM) Equivalent 12:00:00 AM Start of the day 12:00:00 12:00:00 PM Midday / Noon 23:59:59 11:59:59 PM Last second of the day 24:00:00 12:00:00 AM End of the day (transition point) 4. Modern Standards & Limitations
Agreements often state they are valid from the start date at 00:00 until the end date at 24:00 to ensure there is no gap in coverage.
Used to mark the very start of a new calendar day. 24:00:00
A store open "00:00–24:00" is open for the full 24-hour cycle.
The "24:00:00" format is most frequently found in environments where a day's end must be clearly defined: If you are converting between the 24-hour and
Used to mark the exact conclusion of the current day. It is the only time where the hour "24" is permitted, and it must be followed by "00" for minutes and seconds. 2. Common Use Cases
Bus or train timetables may show 00:00 as a departure time (starting the day) and 24:00 as an arrival time (ending the day). A store open "00:00–24:00" is open for the
Shift schedules use 00:00 for shifts starting at midnight and 24:00 for shifts ending at midnight. 3. Conversion Guide