Timezone Abbreviation Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching timezone abbreviation, 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

# Timezone Abbreviation
# ReDoS-safe | RegexVault — Localization > Time Formats

import re

timezone_abbreviation_pattern = re.compile(r'^(?:UTC|GMT|EST|EDT|CST|CDT|MST|MDT|PST|PDT|HST|AKST|AKDT|IST|JST|KST|CST|HKT|SGT|AEST|AEDT|ACST|ACDT|AWST|NZST|NZDT|CET|CEST|EET|EEST|WET|WEST|MSK|BST|WAT|CAT|EAT|SAST)$')

def validate_timezone_abbreviation(value: str) -> bool:
    return bool(timezone_abbreviation_pattern.fullmatch(value))

# Example
print(validate_timezone_abbreviation("UTC"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Time 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

Timezone abbreviations are AMBIGUOUS — IST means Indian Standard Time (+05:30), Irish Standard Time (+01:00), AND Israel Standard Time (+02:00). CST means Central Standard Time (US, -06:00) AND China Standard Time (+08:00). Always prefer IANA timezone identifiers (Asia/Singapore, America/New_York).