Question 1

What is a cron expression?

Accepted Answer

A cron expression is a string of five (or six) fields that defines a recurring schedule for automated tasks. The fields represent minute, hour, day of month, month, and day of week. For example, "0 9 * * 1-5" runs at 9am every weekday.

Question 2

What is the cron syntax for every 5 minutes?

Accepted Answer

Use */5 * * * * to run a job every 5 minutes. The */n syntax means "every n units".

Question 3

Does AWS EventBridge use the same cron syntax?

Accepted Answer

AWS EventBridge uses a 6-field cron syntax that adds a year field and requires either day-of-month or day-of-week to be set to ? (not both). For example: cron(0 9 * * ? *) runs at 9am UTC every day.

Question 4

What is the difference between cron and crontab?

Accepted Answer

Cron is the background daemon that runs scheduled tasks on Unix/Linux systems. Crontab (cron table) is the file that lists the scheduled jobs and their expressions. You edit crontab with the "crontab -e" command.

Cron Expression Builder & Tester

Cron Expression Reference

Cron Expression

Common Presets

Next 8 Runs

Quick Reference

Common Examples