Cron job not running? Diagnose it and catch the next missed run

When you need this

A notification at the end of a script cannot help if cron never starts the script. First check the scheduler and environment, then set an external deadline for the expected result. A missing message becomes a detectable event.

How to connect

1. 1

   Check crontab -l as the correct user, the cron/crond service and its logs. Confirm the timezone.

2. 2

   Run the command with the same permissions, variables and working directory. Use absolute paths and capture stderr in a local log.

3. 3

   After fixing the cause, add a monitor with the real schedule. Skip one test run and wait for its deadline and grace period.

Ready-to-use example

Install Bash, curl and uuidgen on the job server. Save the code as /opt/tickwatch-run.sh, replace the ping URL with your own and use the absolute path to your job. Keep the ping key private. The wrapper preserves the job exit code; a failed monitoring request does not interrupt it. The cron user must be allowed to write to the chosen local log.

#!/usr/bin/env bash
# Save as tickwatch-run.sh; run: bash tickwatch-run.sh /path/to/job.sh
if [ "$#" -eq 0 ]; then echo "Usage: $0 command [args...]" >&2; exit 2; fi
PING='https://ping.tickwatch.dev/YOUR_PING_KEY'
RID=$(uuidgen) || exit 1
ping() {
  curl -fsS --connect-timeout 3 --max-time 5 --retry 2 --retry-max-time 12 \
    -X POST "$PING/$1?rid=$RID" >/dev/null 2>&1 || true
}
finish() {
  code=$?
  trap - EXIT
  if [ "$code" -eq 0 ]; then ping ""; else ping fail; fi
  exit "$code"
}
trap finish EXIT
trap 'exit 130' INT
trap 'exit 143' TERM
ping start
"$@"

0 3 * * * /usr/bin/bash /opt/tickwatch-run.sh /usr/local/bin/job.sh >> /var/log/my-job.log 2>&1

Check before going live

• The command works manually but not in cron: start with PATH, environment variables and relative paths.

• There is no execution attempt: check the crontab owner, service state and schedule expression.

• The job runs late: allow for normal runtime and scheduling delays without masking hours of downtime.

Common questions