Data & Formatting · In-Browser Regular Expression Lab

Cron Expression Regex — Validate Standard 5-Field Schedules

Matches standard Unix crontab schedules (minute, hour, day of month, month, day of week).

Pattern:

Regular Expression Pattern & Flags

Flags:

//none

Live Test String

Match Found

Load Sample:

Match Inspection & Details1 match

Match #1:0 0 * * *

Test Samples Verification Matrix

Expected Valid Samples (Should Match)

0 0 * * * Pass

*/15 * * * * Pass

30 4 1,15 * 5 Pass

Expected Invalid Samples (Must Reject)

0 0 * * Rejected (Pass)

* * * * * * Rejected (Pass)

every day Rejected (Pass)

Code Implementation Generator

// JavaScript / TypeScript (ES6+)
const pattern = /^(?:\*(?:\/[0-9]+)?|[0-9,-\/]+)\s+(?:\*(?:\/[0-9]+)?|[0-9,-\/]+)\s+(?:\*(?:\/[0-9]+)?|[0-9,-\/]+)\s+(?:\*(?:\/[0-9]+)?|[0-9,-\/]+|[a-zA-Z]{3})\s+(?:\*(?:\/[0-9]+)?|[0-9,-\/]+|[a-zA-Z]{3})$/;
const text = "0 0 * * *";

const isMatch = pattern.test(text);
console.log("Is Match:", isMatch);

if (isMatch) {
  const matches = text.match(pattern);
  console.log("Matches:", matches);
}

Regular Expression Token Breakdown

Validates 5 whitespace-separated fields supporting asterisks, ranges, step values, and names. Each component of the regular expression serves a distinct syntactical purpose as mapped below:

Token Pattern	Name / Component	Function & Rule
Field 1	Minutes	0-59, , /5, etc.
Field 2	Hours	0-23, *, 12-18, etc.
Field 3	Day of Month	1-31, *.
Field 4	Month	1-12, JAN-DEC, *.
Field 5	Day of Week	0-6 (Sun-Sat), MON-FRI, *.