---
id: strict-rfc3339
version: "0.7"
license: GNU General Public License Version 3
license_treatment: copyleft
maintenance: abandoned
---

# strict-rfc3339 — Strict, simple, lightweight RFC3339 functions

License: copyleft · Maintenance: abandoned · Downloads: 940.9K/mo

## What it is and what it does

strict-rfc3339 is a lightweight RFC3339 timestamp library that converts between Unix timestamps and RFC3339 strings. It validates RFC3339 format strictly and produces output with either UTC (Z) or local timezone offsets. The package deliberately avoids full timezone libraries and DST complexity by working with offsets and the C time module's local/UTC split.

The library uses only Python's standard time and calendar modules, keeping dependencies minimal. It rejects leap seconds (seconds 60–61) during validation and is limited by the system's time_t size on 32-bit platforms. The package has been abandoned since 2016 and receives no maintenance, so compatibility with modern Python versions and edge cases is not guaranteed.

Use it for:

- Validate incoming RFC3339 timestamps in API requests or log files without pulling in a heavy datetime library.
- Convert Unix timestamps to human-readable RFC3339 strings for REST API responses or logging.
- Generate current time in RFC3339 format with local timezone offset for application timestamps.
- Parse RFC3339 strings back to Unix timestamps for time-series data or event processing.
- Build simple time utilities in projects that must minimize external dependencies.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Converts Unix timestamps to and from RFC3339 strings, with support for UTC or local timezone offsets, using only the standard library's time and calendar modules.

No, unless you have a legacy codebase already using it. The package is abandoned (no releases since 2016), marked Beta, and copyleft-licensed (GPLv3), which restricts use in proprietary code. Modern alternatives like the datetime module, dateutil, or pytz are actively maintained. Use this only if you are already locked into it or need minimal dependencies in a GPL-compatible project.

## Install

pip install strict-rfc3339
uv add strict-rfc3339
poetry add strict-rfc3339

## Installing strict-rfc3339

Before you install: High install friction: the package is abandoned (last release 2016-04-24, no activity for 3764 days) and marked Beta. No runtime dependencies, but the lack of maintenance means bugs and compatibility issues will not be addressed.

License in practice: GPLv3 copyleft license: any code that imports this package must be distributed under GPLv3 or a compatible license. Proprietary or permissively-licensed projects cannot use it without legal review.

Quickstart:

import strict_rfc3339

# Validate an RFC3339 string
valid = strict_rfc3339.validate_rfc3339("2013-03-25T12:42:31+00:32")

# Convert RFC3339 to Unix timestamp
timestamp = strict_rfc3339.rfc3339_to_timestamp("2013-03-25T12:42:31+00:32")

# Convert timestamp to RFC3339 (UTC)
rfc_string = strict_rfc3339.timestamp_to_rfc3339_utcoffset(1364213431)

Verify before relying:

- Whether the package works reliably on modern Python versions (3.10+) despite being abandoned since 2016
- Whether leap second handling limitations affect your use case
- Whether 32-bit time_t limitations (dates ~1901–2038) are relevant to your application

## Package facts

- License: GNU General Public License Version 3 (copyleft)
- Python support: unspecified
- Install friction: high
- Maintenance: abandoned
- Downloads: 940.9K/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

rfc3339 timestamp conversion, unix timestamp to rfc3339, rfc3339 validation, timestamp formatting, timezone offset handling, rfc3339 parser, datetime to rfc3339, timestamp-handling, rfc3339, abandoned

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