What is a cron expression?

A cron expression is a string of 5 fields separated by spaces that defines a recurring schedule: minute, hour, day of month, month, and day of week. For example, 0 9 * * 1-5 means 9:00 AM every weekday.

Is my data sent to a server?

No. Parsing and scheduling calculations run entirely in your browser using JavaScript.

Does the tool support @daily and other shorthand expressions?

Yes. Common shortcuts like @hourly, @daily, @weekly, @monthly, and @yearly are all supported.

What time zone are the next run times shown in?

Run times are shown in your local browser time zone by default.

Cron expression explainer

Cron expression explainer is a browser-based tool that translates 5-field cron syntax into plain English and shows upcoming run times. Enter any expression and see the schedule explained instantly along with the next five execution times.

Cron expression

*/15Minute

*Hour

*Day of month

*Month

*Day of week

Quick fill

5-field format: minute · hour · day of month · month · day of week

Dedicated pages

Direct links for specific cron use cases.

Cron job schedule explainer

Explain cron job schedules in plain English and preview the next run times. All processing runs in your browser.

Cron syntax tester

Test and validate cron syntax instantly. See the plain-English meaning of any cron expression and preview upcoming run times.

Cron expression generator

Generate and explain cron expressions with instant plain-English output and next run time preview. Runs entirely in your browser.

How to understand a cron expression

Type or paste your cron expression into the input field (e.g. 0 9 * * 1-5).
The tool translates it into plain English instantly.
View the next 5 scheduled run times based on the expression.
Use the quick-fill buttons to start with a common schedule like @daily or @weekly.

Common uses

Verifying that a cron job is scheduled at the intended time before deploying, use Unix timestamp converter to check the exact epoch time of a past run
Explaining a cron expression to a colleague who is not familiar with the syntax
Debugging why a scheduled task ran at an unexpected time. The date calculator helps work out how many days ago or until a specific date

Technical specification

Algorithm or formula: Plain-English translation uses the cronstrue library. Next-run preview is a custom 5-field parser that expands ranges, lists, and step values, then walks forward minute-by-minute to find the next matching slots.
Browser API or library: cronstrue 3.14 (~8 KB, lazy-loaded). Native JavaScript Date for time arithmetic.
Input limits: Standard 5-field cron syntax plus @hourly, @daily, @weekly, @monthly, and @yearly shorthands. Quartz 6 and 7-field syntax is not supported.
Output: Plain-English description and the next 5 run times in the browser's local time zone.
Known limitations: No DST adjustment beyond what the browser Date object provides. Special characters ?, L, W, and # (Quartz extensions) are not parsed in the preview.

Frequently asked questions

What is a cron expression?: A cron expression is a string of 5 fields separated by spaces that defines a recurring schedule: minute, hour, day of month, month, and day of week. For example, 0 9 * * 1-5 means 9:00 AM every weekday.
Is my data sent to a server?: No. Parsing and scheduling calculations run entirely in your browser using JavaScript.
Does the tool support @daily and other shorthand expressions?: Yes. Common shortcuts like @hourly, @daily, @weekly, @monthly, and @yearly are all supported.
What time zone are the next run times shown in?: Run times are shown in your local browser time zone by default.

Reviewed and tested May 26, 2026.