Cron Mastery

Master OpenClaw's timing systems. Use for scheduling reliable reminders, setting up periodic maintenance (janitor jobs), and understanding when to use Cron v...

Security Scan

The skill's instructions, examples, and file access align with a cron/scheduling maintenance guide; nothing requests unrelated credentials or installs, though some maintenance steps are potentially destructive and should be used carefully.

Purpose & Capability

Name and description promise cron/scheduling guidance and the SKILL.md focuses exclusively on scheduling patterns, payload types, cleanup, and gateway behavior. Required binaries/env/configs are none and that is consistent with an instruction-only reference skill.

Instruction Scope

Instructions remain within scheduling/maintenance scope but include potentially destructive operational steps (e.g., manual deletion of ~/.openclaw/state/cron/jobs.json and restarting the gateway) and explicit advice to run janitor actions in the 'main' session with full tool access. These actions are relevant to cron maintenance but require care and appropriate privileges.

Install Mechanism

No install spec or code is provided (instruction-only), so nothing is written to disk or fetched during install.

Credentials

The skill requests no environment variables or credentials. Example payloads reference delivery channels (e.g., Telegram) and specific numeric recipient IDs, but the skill does not itself request tokens — delivering via those channels would rely on the agent's preexisting integrations. This is coherent but users should be aware examples assume external integrations exist and that delivering messages requires appropriate credentials elsewhere.

Persistence & Privilege

always is false and the skill does not request persistent presence. It does recommend using the 'main' session for janitor tasks because it needs broader tool access; that is a legitimate runtime guidance rather than a privilege escalation in the skill manifest.

Assessment

This is a documentation-only skill about scheduling and maintenance; it appears coherent with that purpose. Before using it: (1) confirm your OpenClaw version matches the stated compatibility (v2026.2.15+); (2) back up ~/.openclaw/state/cron/jobs.json before following deletion guidance — removing that file and restarting the gateway is destructive and should be a last resort; (3) be cautious granting or using the 'main' session for janitor jobs since it may have full tool access and can delete jobs; (4) examples reference Telegram delivery and hardcoded recipient IDs — ensure any proactive delivery channels are configured and authorized elsewhere and replace example IDs with your own; (5) test templates in a safe environment to verify behavior before running them in production.

Rule #1: Heartbeats drift. Cron is precise.

This skill provides the definitive guide for managing time in OpenClaw 2026.2.15+. It solves the "I missed my reminder" problem by enforcing a strict separation between casual checks (heartbeat) and hard schedules (cron).

The Core Principle

System	Behavior	Best For	Risk
Heartbeat	"I'll check in when I can" (e.g., every 30-60m)	Email checks, casual news summaries, low-priority polling.	Drift: A "remind me in 10m" task will fail if the heartbeat is 30m.
Cron	"I will run at exactly X time"	Reminders ("in 5 mins"), daily reports, system maintenance.	Clutter: Creates one-off jobs that need cleanup.

1. Setting Reliable Reminders (2026.2.15+ Standard)

Rule: Never use act:wait or internal loops for long delays (>1 min). Use cron:add with a one-shot at schedule.

Precision & The "Scheduler Tick"

While Cron is precise, execution depends on the Gateway Heartbeat (typically every 10-60s). A job set for :00 seconds will fire on the first "tick" after that time. Expect up to ~30s of variance depending on your gateway config.

Modern One-Shot Reminder Pattern

Use this payload structure for "remind me in X minutes" tasks.

Key Features (v2026.2.15+):

• Payload Choice: Use AgentTurn with Strict Instructions for push notifications (reminders that ping your phone). Use systemEvent only for silent logs or background state updates.
• Reliability: nextRunAtMs corruption and "Add-then-Update" deadlocks are resolved.
• Auto-Cleanup: One-shot jobs auto-delete after success (deleteAfterRun: true).

CRITICAL: Push Notifications vs. Silent Logs

• systemEvent (Silent): Injects text into the chat history. Great for background logs, but WILL NOT ping the user's phone on Telegram/WhatsApp.
• AgentTurn (Proactive): Wakes an agent to deliver the message. REQUIRED for push notifications. Use the "Strict" prompt to avoid AI chatter.

For push-notification reminders (Reliable):

{
  "name": "Remind: Water",
  "schedule": { "kind": "at", "at": "2026-02-06T01:30:00Z" },
  "payload": {
    "kind": "agentTurn",
    "message": "DELIVER THIS EXACT MESSAGE TO THE USER WITHOUT MODIFICATION OR COMMENTARY:\n\n💧 Drink water, Momo!"
  },
  "sessionTarget": "isolated",
  "delivery": { "mode": "announce", "channel": "telegram", "to": "1027899060" }
}

For background logs (Silent):

{
  "name": "Log: System Pulse",
  "schedule": { "kind": "every", "everyMs": 3600000 },
  "payload": {
    "kind": "systemEvent",
    "text": "[PULSE] System healthy."
  },
  "sessionTarget": "main"
}

Cron Concurrency Rule (Stabilized)

Pre-2026.2.15, the "Add-then-Update" pattern caused deadlocks. While this is now stabilized, it is still best practice to pass all parameters (including wakeMode: "now") directly in the initial cron.add call for maximum efficiency.

2. The Janitor (Auto-Cleanup) - LEGACY

Note: As of v2026.2.14, OpenClaw includes maintenance recompute semantics. The gateway now automatically cleans up stuck jobs and repairs corrupted schedules.

Manual cleanup is only needed for:

• One-shot jobs created with deleteAfterRun: false.
• Stale recurring jobs you no longer want.

Why use sessionTarget: "main"? (CRITICAL)

Sub-agents (isolated) often have restricted tool policies and cannot call gateway or delete other cron jobs. For system maintenance like the Janitor, always target the main session via systemEvent so the primary agent (with full tool access) performs the cleanup.

3. Reference: Timezone Lock

For cron to work, the agent must know its time.

• Action: Add the user's timezone to MEMORY.md.
• Example: Timezone: Cairo (GMT+2)
• Validation: If a user says "remind me at 9 PM," confirm: "9 PM Cairo time?" before scheduling.

4. The Self-Wake Rule (Behavioral)

Problem: If you say "I'll wait 30 seconds" and end your turn, you go to sleep. You cannot wake up without an event. Solution: If you need to "wait" across turns, you MUST schedule a Cron job.

• Wait < 1 minute (interactive): Only allowed if you keep the tool loop open (using act:wait).
• Wait > 1 minute (async): Use Cron with wakeMode: "now".

5. Legacy Migration Guide

If you have old cron jobs using these patterns, update them:

Legacy (Pre-2026.2.3)	Modern (2026.2.15+)
"schedule": {"kind": "at", "atMs": 1234567890}	"schedule": {"kind": "at", "at": "2026-02-06T01:30:00Z"}
"deliver": true in payload	Not needed - announce mode handles delivery
"sessionTarget": "main"	"sessionTarget": "isolated" (default behavior)
Manual ghost cleanup required	One-shots auto-delete (deleteAfterRun: true)
cron.update after cron.add	Single-step cron.add with all properties

Troubleshooting

• "My reminder didn't fire": Check cron:list. Verify the at timestamp is in the future (ISO 8601 format). Ensure wakeMode: "now" is set.
• "Gateway Timeout (10000ms)": This happens if the cron tool takes too long (huge job list or file lock).
  • Fix 1: Manually delete ~/.openclaw/state/cron/jobs.json and restart the gateway if it's corrupted.
  • Fix 2: Run a manual sweep to reduce the job count.
• "Job ran but I didn't get the message": Ensure you are using the Strict Instruction Pattern with agentTurn + announce mode for proactive pings.
• "The reminder message has extra commentary": The subagent is being conversational. Use the strict prompt pattern: "DELIVER THIS EXACT MESSAGE TO THE USER WITHOUT MODIFICATION OR COMMENTARY:\n\n💧 Your message here"