Regex for Date (MM/DD/YYYY) — Pattern Explained with Examples

This regex validates dates in the US MM/DD/YYYY format. It checks that the month is 01–12, the day is 01–31, and the year is four digits, all separated by forward slashes. This pattern is commonly used in North American web forms, document processing, and data exchange systems.

The Pattern

/^(0[1-9]|1[0-2])\/(0[1-9]|[12]\d|3[01])\/\d{4}$/

Pattern Breakdown

Matches

• 01/15/2024
• 12/31/1999
• 06/01/2023
• 02/28/2000
• 07/04/2024

Does NOT Match

• 13/01/2024 — month 13 is invalid
• 01/32/2024 — day 32 is invalid
• 1/1/2024 — missing leading zeros
• 2024/01/15 — wrong order (YYYY/MM/DD)
• 01-15-2024 — hyphens instead of slashes
• 00/01/2024 — month 00 is invalid
• 01/01/24 — year is only 2 digits

Language Examples

JavaScript

const dateRegex = /^(0[1-9]|1[0-2])\/(0[1-9]|[12]\d|3[01])\/\d{4}$/;

console.log(dateRegex.test('01/15/2024'));  // true
console.log(dateRegex.test('13/01/2024'));  // false
console.log(dateRegex.test('01/32/2024'));  // false

// Extract month, day, year
const match = '12/25/2023'.match(dateRegex);
if (match) {
  console.log(`Month: ${match[1]}, Day: ${match[2]}, Year: ${match[3]}`);
}

Python

import re

date_regex = r'^(0[1-9]|1[0-2])\/(0[1-9]|[12]\d|3[01])\/\d{4}$'

print(bool(re.match(date_regex, '01/15/2024')))  # True
print(bool(re.match(date_regex, '13/01/2024')))  # False

# Extract parts
match = re.match(date_regex, '07/04/2024')
if match:
    month, day, year = match.groups()
    print(f'{month}/{day}/{year}')

Common Pitfalls

1. Slash escaping in regex — The / character must be escaped as \/ inside a regex literal. Alternatively, use a different delimiter or construct the regex with new RegExp().

2. DD/MM vs MM/DD confusion — Users from outside the US often expect DD/MM/YYYY. Make sure your user interface clarifies the expected format.

3. February 30 passes — Like the YYYY-MM-DD pattern, this regex does not validate calendar logic. 02/30/2024 passes but is not a real date.

4. Leading zeros matter — 1/1/2024 fails because single-digit months and days are not matched. Decide whether to accept them with an alternative pattern.

Real-World Use Cases

• US-based web forms — Standard date input for addresses, billing, and shipping information
• Document processing — Extracting dates from US government or business documents
• Data migration — Converting legacy MM/DD/YYYY data into ISO 8601 for database storage

FAQ