How do I run a cron job in a specific timezone?

You can set CRON_TZ=America/New_York before your cron expression (if supported), or wrap your command with TZ=America/New_York. Alternatively, calculate the UTC equivalent time and schedule in UTC.

Why did my cron job run at the wrong time?

Common causes: 1) Server is in UTC but you scheduled in local time, 2) DST changed and shifted execution time, 3) Container timezone differs from host, 4) Cloud provider uses UTC by default.

How does DST affect cron jobs?

During DST transitions, cron jobs scheduled between 2-3 AM may run twice (fall back) or not at all (spring forward). Jobs scheduled in UTC are not affected. Consider scheduling critical jobs outside DST transition windows.

FREE TOOL

Cron Timezone Debugger

When will your cron really run? Debug timezone confusion instantly.

crontab -e

$ CRON_EXPRESSION

At 09:30 AM, every day

# quick presets

$ SERVER_TIMEZONE # where cron runs

$ YOUR_TIMEZONE # where you are

timezone_debug.log

$ ./debug_timezone.sh

SERVER EXECUTES AT

09:30

UTC

YOUR LOCAL TIME

10:30

Europe/Warsaw

TIMEZONE OFFSET

+1 hour

🕐

NEXT_EXECUTIONS:

💡

Pro Tip

Schedule critical jobs in UTC to avoid DST issues. Your server runs in UTC, so "0 9 * * *" always means 9:00 UTC.

24h_timeline.sh

$ ./show_timeline.sh --24h

00:00 06:00 12:00 18:00 24:00

09:30 UTC

10:30 Local

Server time

Your local time

Know when it runs. Know when it fails.

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Understanding Cron Timezones

What timezone does cron use?

Cron uses the system timezone by default. Most cloud servers and containers run in UTC. Check with timedatectl or cat /etc/timezone.

DST can break your cron

Jobs at 2-3 AM local time are dangerous. During spring forward, 2:30 AM doesn't exist. During fall back, 2:30 AM happens twice. Use UTC to avoid this entirely.

Common timezone mistakes

✗ Assuming server is in your local timezone
✗ Docker container has different TZ than host
✗ Forgetting about DST when scheduling
✗ Not testing after server migration

Best practices

✓ Use UTC for all cron schedules
✓ Document timezone in crontab comments
✓ Avoid 2-3 AM for critical jobs
✓ Use monitoring to verify execution times

Frequently Asked Questions

Want to dive deeper into timezone issues?

Read: Handling Timezone Issues in Cron Jobs - Complete Guide