Cron Minute Field Regex for JavaScript

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching cron minute field, ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// Cron Minute Field
// ReDoS-safe | RegexVault — Dev & Systems > Cron

const cronMinuteFieldRegex = /^(?:\*(?:\/[1-9]|\/[1-5][0-9])?|(?:[0-9]|[1-5][0-9])(?:-(?:[0-9]|[1-5][0-9]))?(?:\/[1-9]|\/[1-5][0-9])?(?:,(?:[0-9]|[1-5][0-9]))*)$/;

function validateCronMinuteField(input: string): boolean {
  return cronMinuteFieldRegex.test(input);
}

// Example
console.log(validateCronMinuteField("*")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Cron category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Steps (/n) must be >= 1. A step of 0 is invalid and would cause infinite loops or errors in cron implementations. Range start must be <= range end (not validated by regex).