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About

The fastest way to read and build crontab expressions

AG Cron is a free developer tool that instantly decodes crontab expressions into a human-readable schedule description with no sign-up or install, and previews the upcoming run times.

It supports the standard Unix 5 fields (minute, hour, day of month, month, day of week), the *, ,, -, and */n syntax, day/month names, and macro aliases like @daily and @hourly. When you enter an expression, the meaning of each field is broken down into cards so you can immediately see what's wrong.

All parsing and calculation happen entirely within your browser, and none of the values you enter are sent to or stored on any server.

Main features

Natural-language parsing

Instantly explains complex cron expressions in human-readable sentences.

Next-run preview

Calculates and shows the next 8 run times in your browser's time zone.

Field builder & presets

Assemble the minute, hour, day of month, month, and day of week, or start quickly with a preset.

In-browser processing

All calculations happen in your browser only and are never sent to a server.

How to use

Paste a cron expression into the input at the top, or pick a preset.

The explanation sentence, next run times, and per-field breakdown are shown in real time.

Adjust the values with the field builder, then grab the expression with the copy button.

Frequently asked questions
Which cron formats are supported?
The standard Unix crontab 5 fields (minute, hour, day of month, month, day of week) are supported. It parses the *, comma (list), hyphen (range), and */n (interval) syntax, day/month names (MON, JAN, etc.), and macro aliases like @daily and @hourly. Second-level (6-field) expressions are not supported.
Which time zone are the next run times calculated in?
They are calculated and displayed using your browser's local time zone. Server crontabs usually run in the server's time zone (such as UTC), so compare against your actual server time zone for reference.
What do 0 and 7 mean in the day of week?
In cron, the day of week ranges from 0 to 6, where 0 is Sunday. Many implementations also treat 7 as Sunday, so this tool interprets 7 as Sunday too.
Is the expression I enter sent to a server?
No. All parsing and calculation happen entirely within your browser, and no values are sent to or stored on any server.
Resources

Schedule collection

Copy-and-go recipes

Syntax cheat sheet

The 5 fields and special characters at a glance

Macros & aliases

Shorthand expressions like @daily

Guides

Practical guides to truly understand cron and make fewer mistakes

In-browser processing Real-time parsing No sign-up Completely free