24-Hour and 12-Hour Time: Rules and Examples
For 1:00–11:59 PM, add 12 to the hour; for 12:00–12:59 AM, use hour 00. Morning hours 1–11 and noon hour 12 ke
Military Time Converter
Method and units
For 1:00–11:59 PM, add 12 to the hour; for 12:00–12:59 AM, use hour 00. Morning hours 1–11 and noon hour 12 keep their hour. Minutes remain unchanged. The form accepts H:MM or HH:MM in 24-hour mode and H:MM AM/PM in 12-hour mode.
Worked example
00:30 becomes 12:30 AM; 12:00 becomes 12:00 PM; 23:59 becomes 11:59 PM. Conversely, 1:30 PM becomes 13:30.
Assumptions and limits
Hours must be 0–23 in 24-hour form or 1–12 with AM/PM; minutes must be 00–59. The converter does not accept 24:00, seconds, dates or time zones. “Use Current Time” fills the device’s local clock; it does not convert time zones.
Specific questions
Does 12:00 AM mean noon here?
No. The calculator maps 12:00 AM to 00:00 and 12:00 PM to 12:00; NIST recommends naming noon and midnight explicitly when ambiguity matters.
Sources and related calculators
Last reviewed: 2026-09-28.