Free · Browser-based · No sign up

Duration Calculator

Measure elapsed time and calendar differences between two dates.

Local processingYour input stays hereSimple controls

Start & End

Start date and timeEnd date and timeTime zoneDaylight saving conflict

Enter two date-times to calculate the difference.

Calendar years, months and days have variable lengths. Absolute totals measure elapsed seconds; a daylight saving day can contain 23 or 25 hours.

Processed locally in your browser

Your input does not need to be uploaded to an EvryNest server. Nothing is saved automatically.

1
Enter two times
Set a start and end date-time and their shared time zone.
2
Calculate
Measure the elapsed time using that zone's daylight saving rules.
3
Compare units
Read calendar years and months alongside absolute elapsed totals.

Is my input uploaded?

The tool processes your input in your browser. It does not upload your input or automatically save it.

Why can days and total hours differ?

Calendar days follow the chosen time zone. A daylight saving transition can create a 23-hour or 25-hour day; elapsed totals measure actual seconds.

How are months and years calculated?

Calendar units are measured relative to the start date. Months and years are not converted using a fixed average length.