Abbreviated Month Name (English) Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching abbreviated month name (english), ported and verified for Python. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# Abbreviated Month Name (English)
# ReDoS-safe | RegexVault — Localization > Date Formats

import re

abbreviated_month_name_english_pattern = re.compile(r'^(?:(0?[1-9]|[12][0-9]|3[01])[\-\s](Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[\-\s]((?:19|20)[0-9]{2})|(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+(0?[1-9]|[12][0-9]|3[01]),?\s+((?:19|20)[0-9]{2}))$')

def validate_abbreviated_month_name_english(value: str) -> bool:
    return bool(abbreviated_month_name_english_pattern.fullmatch(value))

# Example
print(validate_abbreviated_month_name_english("15-Jan-2024"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Date Formats category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. 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

DD-Mon-YYYY is common in Oracle databases and UK bank statements. Mon DD, YYYY is common in American printed documents. The month abbreviation is always 3 letters.