# Time Duration Calculator

> Calculate elapsed time between two clock times, including an optional next day.

Page: https://askcalculators.com/calculator/time-duration-calculator/
Definition: https://askcalculators.com/calculator/time-duration-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/time-duration-calculator/schema.json
Version: 1.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/time-duration-calculator/?startTime=09%3A00&endTime=17%3A30&nextDay=0

## Inputs
- startTime: Start time; type=time; required; default=09:00
- endTime: End time; type=time; required; default=17:30
- nextDay: End time is on the next day; type=checkbox; optional; default=false

## Outputs
- duration: Duration; format=text; primary
- totalMinutes: Total minutes; format=number
- decimalHours: Decimal hours; format=number
- totalSeconds: Total seconds; format=integer

## Formula
Duration = end clock time − start clock time (+ 24 hours when next day is selected)

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.