Cron Job Every Day at 3:00 AM – Expression & Examples
The cron expression 0 3 * * * triggers once per day at 3:00 AM server time, every day of the week and every month of the year. The fields break down as: minute 0, hour 3, any day-of-month, any month, any day-of-week. This makes it a consistent daily schedule well suited for off-peak maintenance tasks when user traffic is typically at its lowest.
How It Works
The cron expression 0 3 * * * triggers once per day at 3:00 AM server time, every day of the week and every month of the year. The fields break down as: minute 0, hour 3, any day-of-month, any month, any day-of-week. This makes it a consistent daily schedule well suited for off-peak maintenance tasks when user traffic is typically at its lowest.
Common Use Cases
- Run nightly database backups or exports before business hours begin
- Trigger daily data synchronization between external APIs and internal systems
- Generate and email scheduled reports summarizing the previous day's activity
- Perform nightly cache invalidation or search index rebuilds to keep data fresh for the morning
Monitor a Job on This Schedule
Writing the 0 3 * * * schedule is only half the job. Cron fires silently — if the run is skipped, the server is down, or the script fails, nothing tells you. A heartbeat monitor closes that gap: your job pings a URL on success, and you get an alert the moment an expected run goes missing. CronJobPro can run this schedule for you as an HTTP job, or watch a job you run elsewhere (cron, CI, Kubernetes) with a dead-man's-switch check.
Schedule This Cron Job Now
Create a free CronJobPro account and use 0 3 * * * to schedule HTTP requests automatically — with monitoring, retries, and notifications built in.
Frequently Asked Questions
What does 0 3 * * * mean in cron?
The cron expression 0 3 * * * triggers once per day at 3:00 AM server time, every day of the week and every month of the year. The fields break down as: minute 0, hour 3, any day-of-month, any month, any day-of-week. This makes it a consistent daily schedule well suited for off-peak maintenance tasks when user traffic is typically at its lowest.
How do I use this cron expression?
On Linux/macOS, edit your crontab with crontab -e and add:0 3 * * * /path/to/your/script.sh
Or use CronJobPro to schedule HTTP requests with this expression — no server required.
What timezone does cron use?
By default, cron uses the system timezone. CronJobPro lets you set a specific timezone per job, so your schedules are predictable regardless of server location.