ISO 8601 Log Timestamp Regex for Python

What this pattern does

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

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

import re

iso_8601_log_timestamp_pattern = re.compile(r'^(\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)?')

def validate_iso_8601_log_timestamp(value: str) -> bool:
    return bool(iso_8601_log_timestamp_pattern.fullmatch(value))

# Example
print(validate_iso_8601_log_timestamp("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 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

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.