Cron Syntax Cheat Sheet: How to Read Cron Expressions

Cron expressions are dense but logical. Once you know what the five fields and four special characters mean, you can read — and write — almost any schedule. Here's the cheat sheet.

The five fields

A standard cron line has five space-separated fields, always in this order:

┌───────────── minute (0–59)
│ ┌─────────── hour (0–23)
│ │ ┌───────── day of month (1–31)
│ │ │ ┌─────── month (1–12)
│ │ │ │ ┌───── day of week (0–7, 0 and 7 = Sunday)
│ │ │ │ │
* * * * *  command

The four special characters

• * — every value. * * * * * runs every minute.
• , — a list. 0 8,12,18 * * * runs at 8am, noon and 6pm.
• - — a range. 0 9-17 * * * runs hourly from 9am to 5pm.
• / — a step. */15 * * * * runs every 15 minutes.

You can combine them: 0-30/10 means 0, 10, 20, 30. The pieces apply independently per field, which is what makes cron so expressive.

Common schedules

• */5 * * * * — every 5 minutes.
• 0 * * * * — every hour, on the hour.
• 0 0 * * * — every day at midnight.
• 0 9 * * 1-5 — 9am on weekdays.
• 30 2 * * 0 — 2:30am every Sunday.
• 0 0 1 * * — midnight on the 1st of each month.
• 0 0 1 1 * — midnight on January 1st.

Macros (shorthand)

Many cron implementations accept named shortcuts: @hourly, @daily (midnight), @weekly (Sunday midnight), @monthly and @yearly. They're easier to read than the five-field equivalents and mean exactly the same thing.

The day-of-month / day-of-week gotcha

This trips up almost everyone. When both the day-of-month and day-of-week fields are restricted (neither is *), cron runs when either matches — not both. So 0 0 13 * 5 fires on the 13th of every month and on every Friday, not only on Friday the 13th. If you need a specific weekday-and-date combination, you generally add a check inside the job itself.

Timezones

Cron runs in the server's timezone, which is often UTC. A job scheduled for 0 9 * * * fires at 9am server time, which may not be 9am where you are. Always confirm the server's timezone before relying on a schedule.

Test before you trust

The safest way to verify a cron line is to see its next run times. Paste any expression into our cron explainer for a plain-English breakdown and the next five fire times in your local timezone. If your job reads timestamps, the Unix timestamp converter pairs nicely.