openclaw - 💡(How to fix) Fix cron: one-shot --at broken when using --tz (IANA timezone) [1 comments, 2 participants]

Summary

One-shot --at cron jobs produce incorrect (or null) scheduled times when --tz (IANA timezone) is provided.

Reproduction

openclaw cron add --name "test-tz" \
  --at "2026-05-06T10:00" \
  --tz "America/Chicago" \
  --system-event "one-shot with tz"

Expected: Job scheduled for the correct UTC instant (15:00Z on 2026-05-06 during CDT). Actual: Incorrect at value stored → job never fires or fires at the wrong time.

Root Cause

The offset-less datetime + --tz path in the cron CLI (parseOffsetlessIsoDateTimeInTimeZone / parseAt + getTimeZoneOffsetMs) uses a fragile double-offset correction:

const naiveMs = new Date(`${raw}Z`).getTime();
const resolvedMs = naiveMs - getTimeZoneOffsetMs(
  naiveMs - getTimeZoneOffsetMs(naiveMs, timeZone),
  timeZone
);

This does not reliably convert wall time in the target IANA zone to a correct UTC instant (especially across DST transitions). The resulting at/atMs stored in the job schedule is wrong.

The explicit-offset path (--at "2026-05-06T10:00-05:00") works because it falls through to parseAbsoluteTimeMs + Date.parse. Only the documented --tz path for one-shots is broken.

Affected Code

• CLI parsing: src/cli/cron-cli/ (parseAt, parseOffsetlessIsoDateTimeInTimeZone, getTimeZoneOffsetMs)
• Runtime consumption: computeJobNextRunAtMs (jobs module) which trusts the stored at value

Suggested Fix

Replace the naive offset dance with a correct wall-time → UTC conversion (e.g. using Intl.DateTimeFormat parts in reverse or a library like temporal-polyfill). Add unit tests covering:

• Non-DST zone (America/Chicago in winter)
• DST zone (America/Chicago in summer)
• Zones with non-hour offsets (Asia/Kolkata)
• Edge case near DST transition

Test Case to Add

// src/cli/cron-cli/shared.test.ts or new parse-at.test.ts
it("parseAt respects --tz for offset-less datetime (DST)", () => {
  // 10:00 America/Chicago on 2026-05-06 (CDT, UTC-5) → 15:00Z
  const result = parseAt("2026-05-06T10:00", "America/Chicago");
  expect(result).toBe("2026-05-06T15:00:00.000Z");
});

it("parseAt respects --tz for offset-less datetime (standard time)", () => {
  const result = parseAt("2026-01-15T10:00", "America/Chicago");
  expect(result).toBe("2026-01-15T16:00:00.000Z"); // CST = UTC-6
});