at

Schedule a one-time command to run at a specified time.

low risk

interactive breakdown — edit the command and press Explain

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What it does

at schedules commands for one-time execution at a specific future time, unlike crontab which recurs. Jobs are queued in /var/spool/at and run even if the user logs out. The atq command lists pending jobs; atrm removes them.

Examples

echo 'systemctl restart nginx' | at 23:00Schedule nginx restart at 11 PM · explain & risk-check →

at 14:30 tomorrow <<< 'bash /opt/scripts/backup.sh'Schedule backup for tomorrow afternoon · explain & risk-check →

atqList pending at jobs · explain & risk-check →

atrm 3Remove job number 3 from queue · explain & risk-check →

Pro tip

Use `at` for maintenance tasks that should run exactly once (e.g., applying a configuration change at a specific time). Unlike cron, there's no risk of it accidentally running repeatedly.

Related

crontab systemctl logger

Open the full explainer →More in System & Processes

Reference text is hand-written and may be incomplete — check man at for your version. Test destructive commands on a non-production system first.