date-time calculator
Military Time Calculator
Convert between 12-hour AM/PM and 24-hour military time notation.
Time arithmetic
Convert 12-hour and 24-hour time
Result
Enter time values and choose Calculate.
Formula version 1.0.0 · Date and time-zone rules are excluded.
How to use this calculator
- Choose the conversion direction.
- Enter the time using the example format shown.
- Select Calculate.
- Read the normalized result and calculation steps.
Symbols and units
| Symbol | Meaning | Unit or domain |
|---|---|---|
HH | Hour | 1–12 with AM/PM or 00–23 |
MM | Minute | 00–59 |
SS | Optional second | 00–59 |
Checked examples
Afternoon conversion
Inputs: 2:35 PM
Calculation: 2 + 12 = 14
Result: 14:35
PM hours except 12 gain 12.
Check: time-basics.test.ts — converts 12-hour to 24-hour
Midnight
Inputs: 00:00
Calculation: 0 mod 12 = 12 AM
Result: 12:00 AM
00:00 is midnight.
Check: time-basics.test.ts — handles midnight/noon
Assumptions, rounding, and limits
- This converts notation only; no date or time zone is inferred.
- Noon is 12:00 PM and midnight is 12:00 AM.
- Minutes and seconds must be 00–59.
- Seconds remain optional.
Frequently asked questions
Is military time always a time zone?
No. Here it means 24-hour clock notation only.
What is noon?
12:00 PM equals 12:00 in 24-hour notation.
What is midnight?
12:00 AM equals 00:00.
Sources and review
- BIPM: SI Brochure — Accepted units of time and SI second
- W3C: Date and Time Formats — 24-hour time notation
- Formula version
- time.military@1.0.0
- Formula review
- Equatara formula review
- Editorial review
- Equatara editorial review
- Last verified
- 2026-10-25
- Applicability
- Global clock arithmetic without dates, zones, payroll, or legal rules.
- Next review
- On material change or by 2028-10-25.
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Found a problem?
Report a formula, result, example, source, or accessibility issue through the calculator correction process. Do not include sensitive input values.