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Free Online Time Calculator

Add or subtract signed HH:MM:SS durations. Hours may exceed 24; minutes and seconds must be below 60.

Your input stays on this device. Processing is bounded; regex runs in a worker with a two-second timeout.

Result



How to use Time Calculator
Add or subtract signed HH:MM:SS durations. Hours may exceed 24; minutes and seconds must be below 60.
  1. Set Text.
  2. Run the tool, review the result and its stated limitations, then copy or download if needed.
Example & practical use
Add or subtract signed HH:MM:SS durations. Hours may exceed 24; minutes and seconds must be below 60. The example below demonstrates Text.
Example input:
{
  "text": "01:30:00\n00:45:00"
}
Expected result (relevant fields):
"02:15:00"
Features & result limitations
Add or subtract signed HH:MM:SS durations. Hours may exceed 24; minutes and seconds must be below 60.
Frequently asked questions
What inputs does Time Calculator accept?
Text
How should I interpret the Time Calculator result?
Add or subtract signed HH:MM:SS durations. Hours may exceed 24; minutes and seconds must be below 60.
Where does Time Calculator process my data?
Inputs are processed locally in your browser. Submitted text is not sent to external services. A successful-run event increments an aggregate tool counter without your input.