ISO 8601 Duration Calculator は何をしますか？
ISO 8601 Duration Calculator はブラウザ上でデータやファイルを変換するツールで、結果と制限を明確に示します。 検証済みの機能： ISO duration output, Negative durations, Exact milliseconds, Local-time inputs.
Elapsed duration is not calendar duration
Use this page for exact milliseconds and fixed 24-hour-day arithmetic. Do not use it for business days, billing months, age calculations, or recurring calendar rules.
使い方
- Enter complete Start date and time and End date and time values in the browser’s current zone.
- Select Calculate; reversing the values produces a negative duration.
- Copy the ISO day/time form together with total days, hours, or milliseconds required by the next system.
実際の入出力例
Measure one day, one hour, one minute, and one second
入力
Start: 2026-01-01 00:00:00
End: 2026-01-02 01:01:01出力
ISO 8601 duration: P1DT1H1M1S
Total hours: 25.017
Milliseconds: 90,061,000The calculation subtracts the two instants and expresses full 24-hour days plus the remaining time.
一般的なエラーと対処
| 症状 | 原因 | 対処 |
|---|---|---|
| A month-long interval is not shown as P1M. | Months have different lengths, while this page reports exact elapsed 24-hour days. | Use a calendar-aware date library when month or year units must follow calendar arithmetic. |
| The elapsed hours around a DST change are not 24 for adjacent local dates. | Browser-local times can cross an offset transition. | Use Time Zone Converter to inspect the instants and choose UTC inputs for fixed elapsed-time calculations. |
Important behavior of Duration Calculator
このツール固有の制限： Elapsed days are exact 24-hour units; calendar months and business-day rules are intentionally excluded.
標準と実装の参考資料
- W3C XML Schema — duration (opens in a new tab)Documents the PnYnMnDTnHnMnS lexical family used for duration values.
- MDN — datetime-local input (opens in a new tab)Explains why a datetime-local value contains no time-zone identifier.
Duration Calculator — FAQ
Does the Duration Calculator upload my input?
No. Processing runs in the current browser tab, and the page does not send tool input to a KitLumi processing endpoint.
What input does the Duration Calculator accept?
It accepts a start and end date with seconds. The workspace checks the input and reports malformed or unsupported values before it produces a result.
What does the Duration Calculator produce?
It produces ISO 8601 days/time notation plus total days, hours, and milliseconds. Copy and download controls appear when the output format supports them.
What limitation should I know?
Elapsed days are exact 24-hour units; calendar months and business-day rules are intentionally excluded.
更新内容
実質的な更新： Duration Calculator: Added ISO duration output, Negative durations, Exact milliseconds, Local-time inputs, responsive controls, explicit runtime disclosure, and task-specific examples and limitations.