Cron job every 15 minutes
To run a cron job every 15 minutes, use */15 * * * *. Every 15 minutes.
- Free
- No Sign-Up
- Runs in Your Browser
Runs
Next Runs
Your time zoneSaturday10 Oct 2026, 23:15
Saturday10 Oct 2026, 23:30
Saturday10 Oct 2026, 23:45
Sunday11 Oct 2026, 00:00
Sunday11 Oct 2026, 00:15
Crontab Line
*/15 * * * * /path/to/job.sh >> /var/log/cron-job.log 2>&1
Cron Expression Generator
*/15 * * * * explained
Expression*/15 * * * *
MeaningEvery 15 minutes
Runs per Week672
Crontab Line*/15 * * * * /path/to/job.sh
systemd OnCalendar*:00/15
Time ZoneThe server's, unless CRON_TZ is set
Steps like */15 line up with the clock, not with the moment you saved the crontab: */15 runs at :00, :15, :30 and :45 every hour. Cron has no way to say "15 minutes after the last run".
If a run can take longer than the gap between runs, stop runs overlapping with flock: */15 * * * * flock -n /tmp/job.lock /path/to/job.sh. A second copy then exits straight away instead of piling up.
Cron runs jobs with a minimal environment: use full paths, and send output to a log file (>> /var/log/job.log 2>&1) so errors are not lost.
Other Schedules
Every Minute · * * * * *Every 2 Minutes · */2 * * * *Every 5 Minutes · */5 * * * *Every 10 Minutes · */10 * * * *Every 15 Minutes · */15 * * * *Every 30 Minutes · */30 * * * *Every Hour · 0 * * * *Every 2 Hours · 0 */2 * * *Every 6 Hours · 0 */6 * * *Every 12 Hours · 0 */12 * * *Every Day at Midnight · 0 0 * * *Every Day at 2am · 0 2 * * *Every Day at Noon · 0 12 * * *Twice a Day · 0 0,12 * * *Every Weekday at 9am · 0 9 * * 1-5Every Weekend Day at 10am · 0 10 * * 6,0Every Monday · 0 0 * * 1Every Sunday · 0 0 * * 0First Day of Every Month · 0 0 1 * *The 15th of Every Month · 0 0 15 * *Every Quarter · 0 0 1 1,4,7,10 *Once a Year · 0 0 1 1 *
Questions
How do I run a cron job every 15 minutes?
Run crontab -e and add: */15 * * * * /path/to/job.sh
How do I check the cron job ran?
Look in the job's own log if it writes one, or the system log: grep CRON /var/log/syslog on Debian and Ubuntu, or journalctl -u cron (cron.service is crond on RHEL).
What is the systemd timer equivalent of */15 * * * *?
OnCalendar=*:00/15 in a .timer unit. systemd timers can also catch up on missed runs with Persistent=true.
Free Tools
More tools
Cron Expression GeneratorBuild a crontab schedule and see it in plain English with next run times.Chmod CalculatorLinux file permissions in octal and symbolic form, both ways.Firewall Rule GeneratorGenerate iptables, nftables and UFW rules for common server set-ups.Proxmox Resource CalculatorHow many VMs fit on a Proxmox host, with overcommit and reserves.
Run servers for other people?
Frabs stops the abuse their VMs send out, and keeps your network off blocklists.