ISO 8601 Log Timestamp Regex for JavaScript

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching iso 8601 log timestamp, 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

// ISO 8601 Log Timestamp
// ReDoS-safe | RegexVault — Dev & Systems > Log Parsing

const iso8601LogTimestampRegex = /^(\d{4})-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])T([01]\d|2[0-3]):([0-5]\d):([0-5]\d)(?:\.(\d{1,9}))?([+-][01]\d:[0-5]\d|Z)?/;

function validateIso8601LogTimestamp(input: string): boolean {
  return iso8601LogTimestampRegex.test(input);
}

// Example
console.log(validateIso8601LogTimestamp("2024-01-15T10:30:00Z")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Log Parsing 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

Groups: 1=year, 2=month, 3=day, 4=hour, 5=minute, 6=second, 7=subseconds, 8=timezone. Subseconds accept up to 9 digits (nanosecond precision used by Go and Rust). Z = UTC.