⏰ Cron Job Generator - Build Cron Expressions

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:
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Tips: Use full paths for commands and scripts for reliability
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{{ example.expression }}
{{ example.description }}
{{ example.use_case }}
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{{ cronLine }}
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{{ explanation.summary }}

Minute: {{ explanation.minute }}
Hour: {{ explanation.hour }}
Day: {{ explanation.dayOfMonth }}
Month: {{ explanation.month }}
Weekday: {{ explanation.dayOfWeek }}
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1. Edit crontab:

crontab -e

2. Add your cron job:

{{ cronLine }}

3. Save and exit

Other commands:

  • crontab -l - List current cron jobs
  • crontab -r - Remove all cron jobs
  • crontab -u username -e - Edit another user's crontab
⚠️ {{ error }}

ℹ️ About Cron Job Generator

Cron schedules commands on Unix and Linux systems by matching the current minute against rows in a crontab file. A user crontab normally has five time fields followed by the command; system crontabs such as /etc/crontab and files in /etc/cron.d add a username field before the command. The classic format is documented by crontab(5), and the daemon behavior is described in cron(8).

Cron expression format: 

# minute hour day-of-month month day-of-week command
# 0-59   0-23 1-31         1-12  0-7
* * * * * /path/to/command

Supported field values:

  • * matches every value in that field, such as every minute or every month.
  • , lists values, for example 1,15 for the 1st and 15th day of the month.
  • - creates an inclusive range, for example 1-5 for Monday through Friday in the day-of-week field.
  • / applies a step within the field range, for example */15 in the minute field for minutes 0, 15, 30, and 45.
  • Month and weekday names are accepted by common Vixie/Cronie-style implementations, such as JAN, MON, or MON-FRI.

Examples:

  • 0 2 * * * /usr/local/sbin/backup.sh runs a backup every day at 02:00.
  • */15 * * * * /usr/bin/curl -fsS https://example.com/health runs a health check four times per hour.
  • 30 4 1,15 * 5 /usr/local/bin/report runs at 04:30 on the 1st and 15th of each month and also on Fridays on common cron implementations.

Common use cases:

  • Automated backups, cleanup jobs, cache warmers, and database maintenance windows.
  • Report generation, notification batches, file transfers, and data synchronization.
  • Periodic health checks for internal services when a full monitoring system is not required.
  • Developer and operations scripts that need simple host-local scheduling without another queue service.

Reliability and safety notes:

  • Use absolute paths for commands and scripts because cron runs with a small environment. Set SHELL, PATH, MAILTO, or CRON_TZ explicitly when a job depends on them.
  • Cron has one-minute granularity in the classic five-field format. It does not support seconds unless your scheduler uses a nonstandard extension.
  • Step values are evaluated inside one field. For example, */35 in the minute field runs at minute 0 and 35 of each hour, not every 35 elapsed minutes.
  • When both day-of-month and day-of-week are restricted, many Linux cron implementations run the command when either field matches. Test complex schedules before installing them.
  • Daylight-saving time can skip or repeat matching wall-clock times. For catch-up behavior after downtime, dependency ordering, randomized delay, or sleep/wake handling, consider a systemd timer instead of a plain crontab entry.
  • Avoid placing secrets directly in cron command lines. Put credentials in protected files or service-specific environment files and redirect output to logs you can rotate and monitor.

API Usage Example:

POST /api/tools/linux/cron
Content-Type: application/json

{
    "minute": "0",
    "hour": "2",
    "dayOfMonth": "*",
    "month": "*",
    "dayOfWeek": "*",
    "command": "/usr/bin/backup.sh",
    "generateExamples": true
}
Ready