cron Cheatsheet - Job Scheduling

All essential cron commands organized by use case, with 43+ entries you can copy and run directly. Find the right command fast when you need it.

SysOps·43 commands·Last updated 2026-07-21

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Schedule Format 7

* * * * * command

Format: min hour day month weekday

*/15 * * * *

Every 15 minutes (step)

0 */2 * * *

Every 2 hours

0 18 * * 0-6

Daily at 18:00 (0-6 range)

10 2 * * 6,7

Sat/Sun at 2:10 (comma list)

0 0 * * 0

Every Sunday at midnight

0 0 1 * *

Monthly on the 1st at midnight

Special Strings 6

@reboot

Run once at boot

@hourly

Hourly (same as 0 * * * *)

@daily / @midnight

Daily (same as 0 0 * * *)

@weekly

Weekly (same as 0 0 * * 0)

@monthly

Monthly (same as 0 0 1 * *)

@yearly / @annually

Yearly (same as 0 0 1 1 *)

System Cron 6

/etc/crontab

System crontab (adds a user column)

/etc/cron.d/

Drop-in task files (same format)

/etc/cron.hourly/

Hourly scripts dir

/etc/cron.daily/

Daily scripts dir

/etc/cron.weekly/

Weekly scripts dir

/etc/cron.monthly/

Monthly scripts dir

User Crontab 7

crontab -e

Edit the current user's crontab

crontab -l

List the current user's jobs

crontab -r

Remove all jobs for the user

crontab -ri

Remove with confirmation prompt

crontab -u user -e

root edits another user's crontab

crontab -u user -l

View another user's jobs

echo "@reboot echo hi" | crontab

Pipe in jobs quickly

Environment 6

SHELL=/bin/bash

Set the shell cron uses

PATH=/usr/local/bin:/usr/bin:/bin

Set PATH (cron's default is minimal)

MAILTO="admin@example.com"

Mail output to an address

MAILTO=""

Disable mail (no output sent)

HOME=/root

Set the HOME dir

CRON_TZ=Asia/Shanghai

Set the cron timezone

Examples 6

0 2 * * * /path/backup.sh

Nightly backup at 2am

*/5 * * * * curl -s https://example.com/health

Health check every 5 minutes

0 9 * * 1-5 mail -s "Report" team@example.com

Email on weekdays at 9am

0 0 1 * * /path/cleanup.sh

Clean temp files monthly

30 3 * * * /usr/bin/logrotate /etc/logrotate.conf

Rotate logs daily at 3:30

0 0 * * 0 /path/weekly-report.sh >> /var/log/report.log 2>&1

Weekly report with logging

Debugging 5

grep CRON /var/log/syslog

Cron log on Debian/Ubuntu

grep cron /var/log/cron

Cron log on RHEL/CentOS

date

Verify the system timezone

systemctl status cron

Check the cron service status

* * * * * echo test >> /tmp/cron-test 2>&1

Debug: write a test line every minute

Tips

Format: min(0-59) hour(0-23) day(1-31) month(1-12) weekday(0-6, 0=Sun).
* = all, , = list, - = range, / = step.
Use absolute paths in scripts or commands may not be found.
cron's env is minimal; set PATH explicitly in scripts.
Redirect output: command >> /var/log/cron.log 2>&1.
Sun = 0 or 7 depending on distro; standardize on 0.

Official References

Commands are compiled from the official docs below. Click to verify the latest usage.

Linux man-pages

Maintained by LaoHand

Publicly updated on Jul 21, 2026, continuously proofread against official docs.

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