Date & time
Date Difference Calculator
Calculate how much time is between two dates — totals (days/hours/minutes) plus a calendar-style breakdown (years/months/days). Local only.
Inputs
Tip: include a timezone (Z or -05:00) for unambiguous results.
Options
If your inputs don’t include a timezone, choose how to interpret them.
Results
Totals are based on milliseconds between two instants. Calendar breakdown is computed in UTC.
Difference
0y 0mo 0d 8h 30m 0s
End is after start (calendar breakdown uses UTC components).
Total days
0.35
Total hours
8.5
Total minutes
510
Total seconds
30,600
Normalized times
Start (UTC ISO)
2026-02-13T09:00:00.000Z
Start (local)
2026-02-13 09:00:00
End (UTC ISO)
2026-02-13T17:30:00.000Z
End (local)
2026-02-13 17:30:00
What “calendar breakdown” means
The breakdown (years / months / days) is computed in UTC by stepping through whole years, then whole months, then converting the remainder into days/hours/minutes/seconds.
DST & timezones
If you enter local times without a timezone, daylight savings transitions can make a “day” be 23 or 25 hours. For the most predictable results, include a timezone offset or use UTC.
Examples
- 2026-02-13T09:00:00Z → 2026-02-13T17:30:00Z
- 2026-03-01T00:00:00-05:00 → 2026-03-02T00:00:00-05:00
How it works
Inputs are parsed and normalized to UTC; totals use raw milliseconds, while calendar breakdown steps whole years, months, then the remaining days and time.
- Include end adds one second to make inclusive date spans easy.
- Absolute mode drops direction but leaves the calendar math unchanged.
Quick examples
If inputs omit offsets, choose local or UTC parsing to avoid DST surprises.
Mini FAQ
Why do totals and calendar differ?
Totals come from milliseconds; calendar steps months/years first.
Does timezone change the result?
Yes when no offset is provided. Add Z or an offset to lock the instant.
What does include end do?
Adds one second so date-only ranges count the final day.
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