How do you convert 12-hour time to 24-hour military time?

For PM hours (except 12 PM), add 12 to the hour: 1:00 PM becomes 13:00, 8:30 PM becomes 20:30. For 12:00 AM (midnight), the 24-hour time is 00:00. For AM hours (1 AM to 11:59 AM), the numbers remain identical.

How do you convert 24-hour time to 12-hour time?

If the hour is 00, it is 12 AM (e.g., 00:30 is 12:30 AM). If the hour is between 01 and 11, it is AM. If the hour is 12, it is 12 PM. If the hour is 13 or greater, subtract 12 and add PM (e.g., 17:00 - 12 = 5:00 PM).

Why is 24-hour time used in aviation, military, and computing?

24-hour time eliminates any ambiguity between morning (AM) and evening (PM) hours, preventing scheduling mistakes in hospitals, flights, logs, and database records.

Time

12h to 24h Time Converter

Convert between 12-hour standard time (AM/PM) and 24-hour military time formats instantly.

Quick Answer & Summary

To convert 12-hour PM time to 24-hour military time, add 12 to the hours (e.g., 4:20 PM = 16:20). 12:00 AM midnight equals 00:00, and 12:00 PM noon equals 12:00. To convert 24-hour time above 12:00 to 12-hour time, subtract 12 and append PM.

Time Format Conversion Rules

24h = (PM && H ≠ 12 ? H + 12 : (AM && H = 12 ? 0 : H)) : M

Standard military and ISO 8601 24-hour time conversion logic.

12-Hour Format (AM/PM)

24-Hour Format (Military)

The 12-hour clock divides the 24-hour day into two periods (AM from 12:00 midnight to 11:59 AM, and PM from 12:00 noon to 11:59 PM). The 24-hour clock (military time) runs continuously from 00:00 to 23:59 without ambiguity.

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Systems & Security Engineers • Applied Cryptography & High-Performance Web Tools

Updated: August 2026

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Documentation & Guide

How to Use 12h to 24h Time Converter

Type 12-Hour or 24-Hour Time

Type into either input box (e.g. '04:20 PM' or '16:20').

Instant Conversion

The corresponding military or 12-hour AM/PM time converts dynamically.

One-Click Copy

Click 'Copy' to copy the formatted string directly to your clipboard.

Pro Tips

Use for military, hospital shift, pilot, and programmer time conversions

Practical Examples & Conversions

Input

12:00 AM

Output

00:00

Frequently Asked Questions (PAA)

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Authoritative Standards & Citations

Calculations and algorithms on this page are implemented and verified in strict accordance with the following official technical specifications:

International Organization for Standardization

ISO 8601: Date and Time Formats

Internationally accepted standard for representing dates and times.

Internet Assigned Numbers Authority

IANA Time Zone Database (TZDB)

Authoritative historical and current daylight saving time (DST) database.