Cron Expression Generator

Choose a schedule to build a cron expression — it is generated locally in your browser and nothing is sent anywhere.

Cron expression (minute hour day-of-month month day-of-week)

Quick presets

Visual builder

Minute (0-59)

Hour (0-23)

Day of month (1-31)

Month (1-12)

Day of week (0-6, Sun=0)

Next 10 run times (your local time)

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Frequently asked questions

What do the five fields mean?

In order: minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–6, Sunday = 0). Each accepts *, ranges (1-5), lists (1,15) and steps (*/10).

How are the next run times calculated?

The tool expands your expression into the exact minutes/hours/days it matches and steps forward minute by minute from now, in your local timezone, collecting the next ten matches.

Why does day-of-month plus day-of-week behave oddly?

Standard cron treats them as OR when both are set: the job runs if either the day-of-month or the day-of-week matches. This tool replicates that behaviour so the preview matches real cron.

Does this run in my browser?

Yes. Parsing, explanation and next-run calculation all happen locally — nothing is sent anywhere.

How cron expressions work

A standard cron line has five fields: minute hour day-of-month month day-of-week. * means "every", */5 means "every 5", 1-5 is a range, and 1,15 is a list.
Day-of-week uses 0–6 with Sunday = 0. When both day-of-month and day-of-week are restricted, standard cron runs when either matches — this tool follows that same OR rule when listing next runs.
The next-run times are computed in your browser's local timezone. If your server runs in UTC, offset accordingly.
This is classic 5-field cron. Some systems add a seconds field (6-field) or non-standard macros — check your scheduler's docs if it differs.

Why scheduled computing became essential

Multi-user Unix systems needed a dependable way to run recurring maintenance and administrative work without someone manually starting every job. Cron-style scheduling made time-based automation a basic operating-system service.

Why five small fields can express so much

Traditional cron expressions combine minute, hour, day-of-month, month and day-of-week fields. Wildcards and ranges let a compact line represent schedules that would otherwise take many individual timers.