Summary

getNextMatch() / getNextRun() can return timestamps in the past near DST transitions, causing infinite "missed execution" warnings in the scheduler.

Two bugs in localized-time.ts:

1. getTimezoneGMT() derives offsets via new Date(date.toLocaleString(...)) roundtrip — the re-parsed string picks up the host timezone's offset at that wall-clock time, not the target timezone's. Replaced with Intl.DateTimeFormat('en-US', { timeZone, timeZoneName: 'shortOffset' }) to parse the offset directly.

2. set() doesn't account for DST boundary crossings. When setting a field moves the date across a DST transition, the offset changes and local time drifts by the offset delta. Added drift detection and timestamp correction after rebuilding parts.

Reproduction

const { TimeMatcher } = require('node-cron/dist/cjs/time/time-matcher.js')
const tm = new TimeMatcher('* * * * *')
// Run with TZ=America/New_York
console.log(tm.getNextMatch(new Date('2026-03-07T22:32:42-05:00')).toString())
// Before fix: Sat Mar 07 2026 21:33:00 GMT-0500 (1 hour in the past)
// After fix:  Sat Mar 07 2026 22:33:00 GMT-0500 ✅

Verified across America/New_York, America/Los_Angeles, America/Phoenix, and UTC.

Test plan

• * * * * * in DST-observing host TZ returns future timestamp
• */5 * * * * in DST-observing host TZ returns future timestamp
• 0 7 * * * with { timezone: 'America/New_York' } returns next day (~8.5 hours), not Jan 2027
• All above pass in UTC and non-DST host timezones
• Build passes (npm run build)