Time Tools

Work with dates, time zones and recurrences locally in the browser.

Time Tools is a standalone local-first application in the add·ideas Toolbox. Inputs are processed in the browser and are not uploaded.

Version 0.1 scope

• Exact signed epoch conversion through nanosecond precision
• IANA-zone comparison, skipped/ambiguous local-time resolution and transition inspection
• Side-by-side wall-clock and elapsed-duration arithmetic
• Bounded 5/6/7-field cron and strict RFC 5545 RRULE occurrence previews
• Weekend/explicit-holiday business-day arithmetic and escaped UTC iCalendar event export

Named-zone results use the IANA data supplied by the browser runtime and can therefore vary with browser versions. ECMAScript Temporal does not represent leap seconds. The business-day calculator excludes weekends and only the holiday dates supplied by the user; it does not infer regional calendars. See docs/ARCHITECTURE.md and docs/PRIVACY-SECURITY.md.

Development

Requires Node.js 22 and npm 11.

npm ci
npm run check
npm run test:browser

Release

npm run release:artifact creates a deterministic release/time-tools-0.1.0.zip and checksum sidecar.

Licence

GPL-3.0-or-later. Runtime dependencies retain their own licences; see THIRD_PARTY_NOTICES.md.