Cron Expression Parser & Builder
A premium cron scheduler decoder. Input your crontab expressions, parse them instantly into plain human-readable sentences, audit each individual schedule field, and calculate exact upcoming execution triggers.
Input Cron Pattern
Every 15 minutes, between 09:00 AM and 05:59 PM, Monday through Friday.
Popular Cron Templates
Cron Field Breakdown
| Field | Allowed | Raw Input | Resolved Description |
|---|
Next 5 Execution Dates
Cron Schedule Syntax and Standards
Cron represents one of the most reliable scheduling systems in computing. Originated in Unix systems, a standard cron pattern consists of 5 columns representing time increments:
- Minute (0–59): Governs which minute of the hour the task triggers.
- Hour (0–23): Set in 24-hour military notation.
- Day of Month (1–31): Controls calendar dates.
- Month (1–12 or JAN–DEC): Triggers on specific months of the year.
- Day of Week (0–6 or SUN–SAT): Governs which days of the week the task triggers (e.g. 1-5 represents weekdays).
Advanced Special Operators and Automation
Modern DevOps and web development platforms support operators to construct complex intervals:
- The Asterisk (
*): Denotes wildcard, meaning "all possible values". - The Step (
/): Indicates increments. For example,*/10in the minute column runs every ten minutes. - The Range (
-): Triggers throughout a continuous range. For instance,9-17in the hour column matches hours from 9 AM through 5 PM. - The List (
,): Composes discrete steps. For instance,1,15in the day column triggers only on the 1st and 15th of the month.
Frequently Asked Questions
What is a cron expression?
A cron expression is a string of five or six fields separated by white space that represents a schedule for running automated jobs (known as crontabs). The five standard fields are: Minutes, Hours, Day of Month, Month, and Day of Week.
How do special cron characters like *, /, -, and , work?
The asterisk (*) acts as a wildcard meaning "every". The slash (/) denotes increments (e.g. */15 means "every 15"). The hyphen (-) defines ranges (e.g. 1-5 means "1 through 5"). The comma (,) allows you to specify a list of discrete values (e.g. 1,3,5).
Why is day-of-week indexing sometimes 0 or 7 for Sunday?
In standard Unix cron scheduling, both 0 and 7 are treated as Sunday. Days 1 through 6 represent Monday through Saturday respectively.
Are my server cron patterns sent to any backend?
Never! All cron string parsing, validation checks, semantic text translation, and next-execution calendar calculations are processed 100% locally in your browser window using client-side JavaScript. Your automation schedules stay entirely confidential.