Date Range (ISO 8601) Regex for Java

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching date range (iso 8601), ported and verified for Java. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Java project — whether you're validating in a Spring Boot controller, a Jakarta EE service, or a standalone utility class.

Java Implementation

// Date Range (ISO 8601)
// ReDoS-checked | RegexVault — Localization > Date Formats

import java.util.regex.Pattern;

public class DateRangeIso8601Validator {
    private static final Pattern PATTERN =
        Pattern.compile("^((?:19|20)[0-9]{2}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12][0-9]|3[01]))/((?:19|20)[0-9]{2}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12][0-9]|3[01]))$");

    public static boolean validate(String input) {
        return PATTERN.matcher(input).matches();
    }

    // Example
    public static void main(String[] args) {
        System.out.println(validate("2024-01-01/2024-12-31")); // true
    }
}

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Date Formats category and has been checked for ReDoS risk. That matters for Java developers because critical in Java applications since the JVM regex engine uses backtracking and is susceptible to ReDoS without careful pattern design. 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

Capture group 1: start date, group 2: end date. This pattern does not validate that the start date precedes the end date — enforce that at application level. ISO 8601 also supports duration syntax (P1Y/2024-01-01) not covered here.