Verify Cron Job Actually Ran: Confirm Execution

Your cron job is scheduled, but how do you know it actually ran? Learn how to verify job execution and detect when jobs don't execute.

Why Jobs Might Not Execute

Cron jobs can be scheduled but not execute for several reasons:

Cron daemon stops running or crashes
System time changes, causing schedule confusion
Job is disabled or commented out in crontab
User account is locked or disabled
System is powered off during scheduled time
Resource limits prevent job from starting
Syntax errors in crontab prevent execution

Without explicit confirmation, you have no way to know if the job actually ran.

How to Verify Job Execution

Send an explicit ping at the start and end of your job. If the ping doesn't arrive, you know the job didn't execute. The ping must be inside your script, not in the cron line.

Bash Example: Ping on Start and End

#!/bin/bash
set -e
# Ping at start to confirm job began
# Your actual work
./backup.sh
./sync.sh
# Ping at end to confirm job completed
curl -X POST "https://deadmanping.com/api/ping/backup-daily"

Python Example: Timestamp Verification

import requests
import datetime
# Your actual work
start_time = datetime.datetime.now()
perform_backup()
end_time = datetime.datetime.now()
duration = (end_time - start_time).total_seconds()
# Single ping with duration in payload
# In DeadManPing panel: set validation rule "duration" < 3600 (e.g., less than 1 hour)
# Panel will automatically detect if job takes too long
requests.post(f"https://deadmanping.com/api/ping/backup-daily?duration={duration}")

Node.js Example: Execution Confirmation

const https = require('https');
// Your actual work
const startTime = Date.now();
async function run() {
  await performBackup();
  
  // Single ping with duration in payload
  // In DeadManPing panel: set validation rule "duration" < 3600 (e.g., less than 1 hour)
  // Panel will automatically detect if job takes too long
  const duration = Math.round((Date.now() - startTime) / 1000);
  https.request(`https://deadmanping.com/api/ping/backup-daily?duration=${duration}`, { method: 'POST' }).end();
}
run().catch((err) => {
  // If job fails, ping won't arrive - DeadManPing will detect missing ping
  process.exit(1);
});

Bash Example: Check Last Execution Time

#!/bin/bash
# Create timestamp file to track last execution
LAST_RUN_FILE="/tmp/last-backup-run"
# Check if job ran recently (within last 25 hours for daily job)
if [ -f "$LAST_RUN_FILE" ]; then
  LAST_RUN=$(cat "$LAST_RUN_FILE")
  NOW=$(date +%s)
  HOURS_SINCE=$(( (NOW - LAST_RUN) / 3600 ))
  
  HOURS_SINCE=$(( (NOW - LAST_RUN) / 3600 ))
fi
# Update timestamp
date +%s > "$LAST_RUN_FILE"
# Your actual work
./backup.sh
# Single ping with hours since last run in payload
# In DeadManPing panel: set validation rule "hours_since" < 25
# Panel will automatically detect if job hasn't run recently
curl -X POST "https://deadmanping.com/api/ping/backup-daily?hours_since=$HOURS_SINCE"

Verifying Execution with Dead Man Switch

A dead man switch verifies job execution by monitoring whether your explicit ping arrives. If the ping doesn't arrive within the expected interval, you know the job didn't execute—even if cron thinks it ran.

This works for all cases: cron daemon stops, system powered off, job disabled, syntax errors, and more. As long as your script sends a ping when it runs, missing pings indicate the job didn't execute.

Working Examples

See complete, working code examples in our GitHub repository:

View Examples on GitHub →

Start Verifying Job Execution

DeadManPing monitors whether your execution pings arrive. Set up monitoring in 2 minutes, get alerts when jobs don't execute.

Start Monitoring Free

Learn more about cron job monitoring and troubleshooting:

Verify Cron Job Actually Ran: Confirm Execution

Why Jobs Might Not Execute

How to Verify Job Execution

Bash Example: Ping on Start and End

Python Example: Timestamp Verification

Node.js Example: Execution Confirmation

Bash Example: Check Last Execution Time

Verifying Execution with Dead Man Switch

Working Examples

Start Verifying Job Execution

Related Articles

Cron Job Not Executing

Verify Cron Job Completed

Monitor Cron Jobs: One Curl Line, No Migration

Detect Cron Job Skipped