Subtract Time Calculator
Quickly subtract two clock times and see the result in hours, minutes, and seconds—with both signed and absolute differences.
The result is Time A − Time B. Enter seconds optionally; the calculator works within a 24-hour day.
Time A: 12:30:00
Time B: 09:15:30
Difference (A − B): 03:14:30
Absolute difference: 03:14:30
How to Use This Calculator
Enter Time A (minuend)
This is the time you subtract from (e.g., clock-out time).
Enter Time B (subtrahend)
The time to subtract (e.g., clock-in time). Seconds are optional.
Interpret the result
The output shows the signed difference and an absolute duration in HH:MM:SS.
Formula
Seconds A = H₁ × 3600 + M₁ × 60 + S₁
Seconds B = H₂ × 3600 + M₂ × 60 + S₂
Difference = Seconds A − Seconds B
Format Difference into HH:MM:SS (with sign)
Example: 14:20:30 − 09:05:00 = 18930 seconds = 05:15:30.
Why Subtract Times?
- Calculate elapsed shift durations.
- Determine time between events (e.g., sunrise and sunset).
- Subtract running times in media editing.
- Compare schedule differences across time zones.
Frequently Asked Questions
Can I subtract times spanning midnight?
Within a 24-hour day, negative results indicate crossing midnight. Use the absolute difference to get duration regardless of order.
Does it work with 12-hour inputs?
Enter times in 24-hour format. Convert from AM/PM first (e.g., 7:30 PM → 19:30:00).
What about days beyond 24 hours?
This tool focuses on daily clock times. For durations beyond 24 hours, convert to total seconds first.
Can I use decimal hours?
Not directly. Convert decimal hours to HH:MM:SS before entering (e.g., 7.5 hours → 07:30:00).