⏰

Time Format & Duration Calculator

Convert 12-hour AM/PM to 24-hour military time, break down decimal hours into HH:MM:SS, and measure elapsed duration.

12-Hour Standard Clock (AM/PM)

Example: 2:30 PM (afternoon)

24-Hour Military Format

: HRS

Military Format:1430 hours

Natural Speech: Two thirty in the afternoon (14:30)

Midnight = 00:00 (12:00 AM) • Noon = 12:00 (12:00 PM)

Time Conversion Reference Rules

Exact Formula

PM Hours = (H % 12) + 12

For PM times (except 12 PM), add 12 to the hour. For 12 AM (midnight), the 24-hour time is 00:00.

Example: 2:30 PM = 2 + 12 = 14:30 | 12:45 AM = 00:45

Exact Formula

Mins = (Dec - Hours) × 60

Multiply the decimal remainder by 60 to obtain minutes, then multiply the remaining decimal by 60 for seconds.

Example: 2.5 hrs = 2 hrs + (0.5 * 60) = 2 hrs 30 mins

Exact Formula

H = ⌊S/3600⌋, M = ⌊(S%3600)/60⌋

Divide total seconds by 3600 to find full hours, and take the modulo remainder for minutes and seconds.

Example: 3661 s = 1 hr (3600s), 1 min (60s), 1 sec (1s)