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Time Duration & Date Diff

Calculate exact elapsed time between two dates and convert between time units.

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How to Use Time Duration & Date Diff

  1. Select the Start Date and End Date using the date-time pickers.
  2. View the exact human-readable elapsed duration and broken-down metrics.
  3. Use the Time Unit Conversion Matrix below to convert between time units.

Frequently Asked Questions

How accurate is the date difference calculation?

Calculations are millisecond-accurate based on the native JavaScript Date API and standard UTC timestamps.

Can I convert between time units (e.g. hours to seconds)?

Yes. The interactive unit conversion section lets you convert any amount between milliseconds, seconds, minutes, hours, and days simultaneously.

Sources & References

Primary references: POSIX.1-2024: Seconds Since the Epoch; ECMAScript Language Specification.

Review policy: references and behavior notes are checked whenever the tool implementation changes.