Time & DateGenerated accuracy model review: 2026-05-06

Time Duration accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

1. Convert both times to minutes from midnight. 2. Subtract Start from End. 3. If End < Start, assume the time crossed midnight and add 24 hours (1440 minutes). 4. Convert the result back to Hours and Minutes.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

Start Time: 09:00
End Time: 17:30

Expected outputs

Duration: 8h 30m
Decimal Hours: 8.5
Total Minutes: 510

Known limitations

This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

If the end time is earlier than the start time, the calculator assumes the span crossed midnight once.
The result reflects a single 24-hour cycle and is not intended for multi-day durations.
Breaks are not deducted here; this tool measures raw elapsed time only.

Unit handling

Start Time accepts local time values.
End Time accepts local time values.

Rounding rules

Number displays use up to 2 decimal places in the calculator UI.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current time-duration-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Time Duration.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

Use calculator