---
id: aws-croniter
version: "2.1.1"
license: MIT
license_treatment: permissive
maintenance: active
---

# aws-croniter — A Python utility for AWS cron expressions. Validate and parse AWS EventBridge cron expressions seamlessly.

License: permissive · Maintenance: active · Downloads: 94.5K/mo

## What it is and what it does

AWS Croniter is a Python library for working with AWS EventBridge cron expressions, which follow a different syntax than standard Unix cron. It validates expressions against AWS rules, parses them with detailed error messages, and computes schedule occurrences—including next/previous times, all occurrences in a date range, and conflicts between multiple schedules. The library handles AWS-specific syntax elements like the wildcard `?`, day-of-week aliases (SUN, MON, etc.), and month aliases (JAN, FEB, etc.).

You would use this when building AWS automation tools, scheduling systems, or applications that need to work programmatically with EventBridge cron rules. It combines validation and calculation in one package, eliminating the need to integrate separate tools. The single runtime dependency is python-dateutil, and it requires Python 3.10 or later.

Use it for:

- Validate AWS EventBridge cron expressions before deploying scheduled rules to avoid runtime failures.
- Calculate the next execution time of an EventBridge rule to show users when an event will trigger.
- Find all occurrences of a schedule within a date range for reporting or audit purposes.
- Detect scheduling conflicts between multiple EventBridge rules within a bounded time window.
- Build a cron expression builder or scheduler UI that needs to parse and interpret AWS cron syntax.

## Worth the install?

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

Parses, validates, and calculates occurrences of AWS EventBridge cron expressions, which differ from standard Unix cron syntax.

Yes. The package solves a specific, real problem (AWS cron expression handling) with low install friction, active maintenance, MIT licensing, and no known vulnerabilities. It's appropriate for any project that needs to work programmatically with EventBridge schedules.

## Install

pip install aws-croniter
uv add aws-croniter
poetry add aws-croniter

## Installing aws-croniter

Before you install: Low install friction with a single runtime dependency (python-dateutil). Actively maintained with a recent release.

License in practice: MIT license permits commercial and private use with minimal restrictions—suitable for most projects.

Quickstart:

from aws_croniter import AwsCroniter
from datetime import datetime, timezone

cron_expression = "0 12 15 * ? 2023"
aws_cron = AwsCroniter(cron_expression)
start_date = datetime(2023, 12, 14, tzinfo=timezone.utc)
next_occurrence = aws_cron.get_next(start_date)
print(next_occurrence)

Requires Python 3.10 or later.

Verify before relying:

- Whether the library handles all AWS-specific cron syntax features (?, L, W, #) correctly in practice.
- Performance characteristics when computing conflicts between many schedules or large date ranges.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 94.5K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

AWS EventBridge cron expression parser, validate AWS cron syntax, calculate cron schedule occurrences, AWS cron expression validator, schedule next occurrence calculator, cron expression scheduling library, AWS event scheduling, aws-eventbridge, scheduling, cron-expressions

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