24hr to Standard Time Converter — Convert Hours in Seconds

Easy 24-Hour to Standard Time Converter with ExamplesConverting between 24-hour time (also called military time) and standard 12-hour time with AM/PM is a common task — useful for travel, scheduling, programming, or reading timetables. This article explains the rules clearly, offers step-by-step methods, presents examples, and provides simple conversion tips you can use mentally or implement in code.

What is 24-hour time vs. standard (12-hour) time?

• 24-hour time runs from 00:00 (midnight) to 23:59, using four digits for hour and minute (HH:MM). It avoids ambiguity by assigning each hour a unique number.
• Standard (12-hour) time cycles from 12:00 AM (midnight) through 11:59 AM, then 12:00 PM (noon) through 11:59 PM, using AM/PM to distinguish morning from afternoon/evening.

Basic conversion rules

• Hours between 01:00 and 11:59 remain the same and map to 1:00 AM–11:59 AM.
• 00:00 → 12:00 AM (midnight).
• 12:00 → 12:00 PM (noon).
• Hours between 13:00 and 23:59 subtract 12 to get the PM hour (e.g., 15:30 → 3:30 PM).

Step-by-step conversion (24-hour → 12-hour)

1. Read the hour (HH) and minutes (MM).
2. If HH = 00, set hour to 12 and suffix AM.
3. If 01 ≤ HH ≤ 11, keep hour as-is and suffix AM.
4. If HH = 12, keep hour 12 and suffix PM.
5. If 13 ≤ HH ≤ 23, set hour = HH − 12 and suffix PM.
6. Keep minutes unchanged; display as two digits.

Example: 21:05 → 21 − 12 = 9 → 9:05 PM.

Examples

• 00:00 → 12:00 AM
• 00:30 → 12:30 AM
• 07:45 → 7:45 AM
• 11:59 → 11:59 AM
• 12:00 → 12:00 PM
• 12:01 → 12:01 PM
• 13:15 → 1:15 PM
• 18:00 → 6:00 PM
• 23:59 → 11:59 PM

Quick mental tricks

• For PM times after noon, subtract 12 from the hour (e.g., 17 → 5 PM).
• For midnight hour (00), think “12 AM” not “0 AM.”
• For convenience, remember noon is 12:00 PM and midnight is 12:00 AM.

Converting programmatically (examples)

JavaScript:

function to12Hour(time24) {   const [hh, mm] = time24.split(':').map(Number);   const suffix = hh < 12 ? 'AM' : 'PM';   let hour12 = hh % 12;   if (hour12 === 0) hour12 = 12;   return `${hour12}:${String(mm).padStart(2, '0')} ${suffix}`; } 

Python:

def to_12_hour(time24: str) -> str:     hh, mm = map(int, time24.split(':'))     suffix = 'AM' if hh < 12 else 'PM'     hour12 = hh % 12     if hour12 == 0:         hour12 = 12     return f"{hour12}:{mm:02d} {suffix}" 

Handling invalid input

• Ensure hours are 00–23 and minutes 00–59.
• Accept inputs with or without leading zeros (e.g., “7:5” → “7:05 AM”) by normalizing.

Use cases

• Reading timetables (trains, flights) that use 24-hour format.
• Scheduling meetings across regions where formats differ.
• Programming utilities and user interfaces that accept both formats.

Summary

Converting between 24-hour and 12-hour time is straightforward: handle midnight (00), noon (12), and subtract 12 for hours after noon. Use the small code snippets above to automate conversions in apps or scripts.