Cheat‑Sheet – Military Time Converter

Fast rules, accepted input formats, and pronunciation tips for military (24‑hour) time.

Rules at a Glance

  • 00:xx → 12:xx AM (midnight hour)
  • 12:xx → 12:xx PM (noon hour)
  • 13–23 → subtract 12 and add PM
  • No leading zero in 12‑hour hours

Input Formats We Accept

  • 24‑hour: 1730, 17:30, 17:30:45
  • 12‑hour: 5:30pm, 5:30 pm, 530p, 12am
  • Seconds are optional.

Speak It

  • 0900 → “oh‑nine hundred”
  • 1730 → “seventeen thirty”
  • 0030 → “oh‑thirty”

Pro Tips

  • When reading timetables, if you see 24:00, treat it as 00:00 on the next day.
  • For voice calls, say both the hour and “AM/PM equivalent” to avoid confusion.
  • On forms, write seconds only when needed (HH:MM is usually enough).

Memory Aids

  • Noon starts PM: 12:xx is always PM.
  • Midnight is 00: 00:xx is always AM (12:xx AM).
  • Afternoon rule: 13–23 → subtract 12 for 12-hour.
  • AM rule: 00–11 stay the same (00 → 12 AM).

Accepted Inputs

  • 24-hour: 1730, 17:30, 17:30:45
  • 12-hour: 5:30pm, 5:30 pm, 530p, 12am

Validation Notes

  • Hours must be 00–23 (24:00 allowed only as day end → 00:00 next day).
  • Minutes/seconds 00–59.
  • 12-hour inputs must include AM/PM (or a/p suffix like 530p).

Printable Quick Rules

  1. Write 00–23 for the hour; append minutes/seconds.
  2. To get 12-hour: 00→12 AM; 01–11→AM; 12→12 PM; 13–23 subtract 12 → PM.
  3. Keep minutes/seconds the same.

One-Minute Cheat

  1. 00→12 AM
  2. 01–11→AM
  3. 12→12 PM
  4. 13–23 → (hour−12) PM
  5. Minutes and seconds never change

Keyboard Tips

  • Use numbers only: 1730 converts to 17:30
  • Add p or a to force AM/PM
  • Use colon for clarity: 17:30

Ultra-Quick Memory Joggers

  • “Noon is PM, Midnight is 00.”
  • “Add 12 for PM 1–11.”
  • “Minutes/seconds never change.”

Pronunciation Mini-Guide

  • 04:00 → “oh-four hundred”
  • 13:15 → “thirteen fifteen”
  • 20:45 → “twenty forty-five”