Complete Guide to Cron Expressions and Job Scheduling

Master cron expression syntax with examples for every schedule pattern.

By RiseTop Team · May 2026 · 8 min read

Cron is the standard job scheduling system on Linux and Unix systems. A cron expression defines when a task should run using five fields.

Cron Expression Format

FieldValuesSpecial Chars
Minute0-59, - * /
Hour0-23, - * /
Day of Month1-31, - * /
Month1-12, - * /
Day of Week0-7, - * /

Common Patterns

ScheduleExpression
Every 5 minutes*/5 * * * *
Every hour0 * * * *
Every day at midnight0 0 * * *
Every Monday at 9am0 9 * * 1
Every weekday at 8am0 8 * * 1-5

Frequently Asked Questions

What does */5 mean in cron? +
It means every 5 units. In the minute field it means minutes 0, 5, 10, 15, etc. In the hour field it means every 5 hours.
How do I troubleshoot cron jobs not running? +
Check syntax with crontab -e, verify user permissions, use absolute paths, ensure cron daemon is running, and check system logs.
Can I test a cron expression without waiting? +
Yes. Use RiseTop Cron Expression Generator to see next execution times instantly.

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