crontab
Parse and use crontab schedules in Python
Decision gist · record as of 2026-08-14
Yes, with conditions. The package is stable, has no dependencies, and solves a specific problem well for applications that need to parse and schedule tasks using standard cron syntax. However, the aging maintenance status (no active development in over a year) and high install friction (source distribution) mean you should verify compatibility with your target Python version before relying on it for new projects. If you need active maintenance or additional scheduling features, consider alternatives.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- High install friction due to source distribution format.
- Package is in production/stable status with recent maintenance (last commit 2025-07-10) and no known vulnerabilities, but has not received active development in over a year.
License · maintenance · safety
GNU LGPL v2.1 (copyleft) — Licensed under GNU LGPL v2.1 (copyleft). Any derivative work or modification must be released under compatible terms; linking in a proprietary application requires careful license review.
last release 2025-07-09 (401 days) · last repo commit 2025-07-10 · 337 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 1,294,223 downloads/mo, #4,095 on PyPI
Alternatives
Verify before relying
pip install crontab
from crontab import CronTab
from datetime import datetime
entry = CronTab('25 * * * *')
delay = entry.next(datetime(2011, 7, 17, 11, 25))
print(delay) # 3600.0- Whether the package works reliably with Python 3.13+ given the aging maintenance status
- Performance characteristics when parsing complex or deeply nested cron expressions
What it is and what it does
This package provides a Python interface to parse standard crontab schedule syntax and compute when a scheduled task should next run. It accepts 5–7 field crontab entries (seconds, minutes, hours, day of month, month, day of week, year) and supports common cron syntax including wildcards, ranges, step values, lists, and day/month abbreviations. It also recognizes convenience aliases like @hourly and @daily.
The main use case is determining the delay in seconds from the current time (or a specified datetime) until the next scheduled execution. The package has no runtime dependencies, making it lightweight for embedding in scheduling systems or task runners that need to calculate cron-based execution times without external service calls.
Use it for
- Calculate next execution time for a cron job in a Python scheduler or task queue
- Validate and parse user-supplied crontab expressions in a web application
- Determine when a recurring background task should run next given a cron schedule
- Build a cron-based job runner that needs to compute delays between executions
- Convert crontab syntax to human-readable descriptions of when tasks will run
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, with conditions.
The package is stable, has no dependencies, and solves a specific problem well for applications that need to parse and schedule tasks using standard cron syntax. However, the aging maintenance status (no active development in over a year) and high install friction (source distribution) mean you should verify compatibility with your target Python version before relying on it for new projects. If you need active maintenance or additional scheduling features, consider alternatives.
Install
crontab on PyPI
Before you install
High install friction due to source distribution format. Package is in production/stable status with recent maintenance (last commit 2025-07-10) and no known vulnerabilities, but has not received active development in over a year.
License in practice
Licensed under GNU LGPL v2.1 (copyleft). Any derivative work or modification must be released under compatible terms; linking in a proprietary application requires careful license review.
Quickstart
pip install crontab
from crontab import CronTab
from datetime import datetime
entry = CronTab('25 * * * *')
delay = entry.next(datetime(2011, 7, 17, 11, 25))
print(delay) # 3600.0Verify before relying
- Whether the package works reliably with Python 3.13+ given the aging maintenance status
- Performance characteristics when parsing complex or deeply nested cron expressions
Package facts
| License | GNU LGPL v2.1 copyleft |
| Python support | Not specified |
| Install friction | High. Source build required |
| Runtime dependencies | None |
| Maintenance | Aging 401 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 1,294,223 / month, #4,095 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableLicense :: OSI Approved :: GNU Lesser General Public License v2 (LGPLv2)License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)License :: OSI Approved :: GNU Library or Lesser General Public License (LGPL)Programming Language :: PythonProgramming Language :: Python :: 2.7Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.2Programming Language :: Python :: 3.4Programming Language :: Python :: 3.5Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9 |
Evidence: crontab-1.0.5.tar.gz
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See also cronsim · python-crontab · croniter · cronex · aiocron · local-crontab · pycron · cron-descriptor · quartz-cron-checker · cron-converter