Crontab Generator

Crontab (cron table) is a configuration file used by the cron daemon on Unix/Linux systems to schedule recurring tasks. Each line contains five time fields (minute, hour, day of month, month, day of week) followed by the command to execute. The cron daemon checks every minute and runs commands whose time patterns match the current time.

Run "crontab -e" in your terminal to edit your personal crontab. Use "crontab -l" to list current entries and "crontab -r" to remove all entries. The system-wide crontab is at /etc/crontab. Each user can have their own crontab file.

Asterisk (*) means "every" value. Comma (,) separates multiple values like 1,3,5. Hyphen (-) defines ranges like 1-5. Slash (/) defines step values like */5 meaning every 5 units. These can be combined: 1-30/5 means every 5th minute from 1 to 30.

Use the expression "*/5 * * * *" which means every 5th minute, every hour, every day. The */5 in the minute field means "at minutes 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55".

Cron is the daemon (background service) that runs scheduled tasks. Crontab is the configuration file that tells cron when to run what. Think of cron as the engine and crontab as the schedule. You interact with crontab to manage scheduled jobs.