clockworktz documentation

clockworktz converts, formats and parses dates across time zones, and it gets the weird zones right: half-hour and 45-minute offsets, 30-minute DST, skipped days, negative DST and historical local mean time. Local times that fall inside a DST gap or overlap resolve exactly the way Temporal resolves them.

These docs are plain GitHub-flavoured Markdown. You can read them on clockworktz.dev/docs or on GitHub; the content is the same in both places.

import { fromUTC, interpretLocal } from 'clockworktz'

fromUTC('2024-07-15T14:00:00Z', 'Australia/Lord_Howe').local
// '2024-07-16 00:30:00.000'

// 02:30 doesn't exist in New York on 10 March 2024: it resolves to 03:30 EDT
interpretLocal('2024-03-10T02:30:00', 'America/New_York').local
// '2024-03-10 03:30:00.000'

At a glance#

• Zero runtime dependencies. The core uses the platform's Intl API (about 21 kB gzipped, about 11 kB minified when you import only fromUTC).
• Host independent. Results never depend on the timezone of the machine running the code.
• Two engines. system-intl uses the OS or browser timezone data. embedded-tzdb uses a pinned IANA tzdb release (30 kB gzipped) for identical results everywhere, with optional signed updates.
• ESM and CommonJS, with complete TypeScript types.
• Node.js 20 or later, or any browser with Intl.DateTimeFormat time zone support.

Where to start#

Links#

• Source on GitHub
• Package on npm
• Changelog
• Report an issue