Bug Report: Cron nextRunAtMs Calculation Error for Cross-Day Schedule

Environment

• OpenClaw Version: 2026.2.3-1
• Node.js: v22.22.0
• OS: Linux (OpenCloudOS 9, kernel 6.6.117)
• Timezone: Asia/Shanghai (UTC+8)

Summary

Cron scheduler incorrectly calculates nextRunAtMs when a job is updated/created in the evening and the next scheduled time is the following morning. It skips the next occurrence and schedules for the day after.

Steps to Reproduce

1. Create/update a daily cron job at 21:53 (Feb 5, 2026)

   • Schedule: 0 10 * * * (daily at 10:00 AM)
   • Timezone: Asia/Shanghai

2. Expected: nextRunAtMs should be Feb 6, 2026 10:00 (12 hours later)

3. Actual: nextRunAtMs was set to Feb 7, 2026 10:00 (36 hours later, skipping Feb 6)

Evidence

Job Configuration:

{
  "id": "d369ad13-b554-4123-aad0-7a5367a76b99",
  "name": "用药提醒-热淋清-早10点",
  "createdAtMs": 1770211095092,
  "updatedAtMs": 1770299625973,  // Feb 5, 2026 21:53:45 CST
  "schedule": {
    "expr": "0 10 * * *",
    "tz": "Asia/Shanghai",
    "kind": "cron"
  },
  "state": {
    "nextRunAtMs": 1770429600000  // Feb 7, 2026 10:00:00 CST (WRONG!)
  },
  "enabled": true
}

Time Calculation:

• Job updated: 2026-02-05 21:53:45 CST (timestamp: 1770299625973)
• Next run set to: 2026-02-07 10:00:00 CST (timestamp: 1770429600000)
• Time difference: 36 hours (should be 12 hours)
• Skipped occurrence: 2026-02-06 10:00:00 CST

Run History:

• openclaw cron runs <jobId> returns empty array
• Confirms Feb 6 10:00 AM was never triggered

Expected Behavior

When a cron job with expression 0 10 * * * is updated at 21:53, the next occurrence should be calculated as the next 10:00 AM, which is:

• Current time: Feb 5, 21:53
• Next 10:00: Feb 6, 10:00 (12 hours later)

Actual Behavior

The scheduler incorrectly skips the next occurrence and schedules for:

• Next 10:00: Feb 7, 10:00 (36 hours later)

Additional Context

• Gateway started: Feb 5, 2026 21:23:53 CST
• Job updated: Feb 5, 2026 21:53:45 CST (via openclaw cron update)
• The issue appears to occur specifically in cross-day scheduling scenarios
• Similar cron jobs scheduled for 14:00 and 20:00 on the same day have correct nextRunAtMs values for the current day

Possible Root Cause

The cron expression parser may have an issue with:

1. Date boundary calculations when current time is PM and next occurrence is AM
2. Timezone conversion between Asia/Shanghai and UTC
3. Logic that determines "next occurrence" vs "occurrence after next"

Impact

• Severity: High
• Scheduled jobs miss their first occurrence after being created/updated in the evening
• Affects medication reminders, scheduled tasks, and time-sensitive automations
• Users may not realize jobs didn't run until checking manually

Related Issues

• Previous version (2026.2.2-3) had issue with nextWakeAtMs: null (fixed in 2026.2.3-1)
• This may be a related edge case in the cron scheduler

Workaround

Manual trigger using:

openclaw cron run <jobId>

Or wait for the next day's occurrence (jobs will run normally after the first skipped occurrence).