head to head · open source
apscheduler vs ical4j
apscheduler has 7,678 GitHub stars, 815 forks, 53 open issues and last shipped 8 days ago. ical4j has 841 stars, 225 forks, 162 open issues and last shipped 3 days ago. apscheduler leads on adoption by 813% (7,678 vs 841 stars). apscheduler is written in Python under MIT; ical4j is written in Java under BSD-3-Clause. apscheduler has attracted 11% as many forks as stars, ical4j 27%. ical4j was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (scheduling), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| apscheduler | ical4j | |
|---|---|---|
| GitHub stars | ★ 7.7K | ★ 841 |
| License | MIT | BSD-3-Clause |
| Written in | Python | Java |
| Last push | 2026-10-26 | 2026-10-31 |
| Forks | ⑂ 815 | ⑂ 225 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick apscheduler if
- You weight community size — 7.7K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick ical4j if
- You want the ical4j feature set and don't need the biggest community
- You prefer the BSD-3-Clause license terms
- Your stack matches Java
- You evaluated both and ical4j fits your workflow better
About apscheduler
.. image:: :target: :alt: Build Status .. image:: :target: :alt: Code Coverage .. image:: :target: :alt: Documentation .. warning:: The v4.0 series is provided as a pre release and may change in a backwards incompatible fashion without any migration pathway, so do NOT use this release in production! Advanced Python Scheduler (APScheduler) is a task scheduler and task queue system for Python. It can be used solely as a job queuing system if you have no need for task scheduling. It scales both up and down, and is suitable for both trivial, single process use cases as well as large deployments spanning multiple…
read the full apscheduler overview →
About ical4j
iCal4j iCalendar parser and object model [RFC2445]: [RFC2446]: [RFC2447]: [RFC5545]: [RFC5546]: [RFC6047]: [RFC6868]: [RFC7808]: [RFC7953]: [RFC7986]: [RFC7529]: [RFC9073]: [RFC9074]: [RFC9253]: [mavenrepo]: [Java Legacy Date Time Code]: [Introduction]: introduction [Setup]: setup [System requirements]: system requirements [Release downloads]: release downloads [Install with Maven]: install with maven [Install with Gradle]: install with gradle [Usage]: usage [Examples]: examples [References]: references [Specifications]: specifications [Configuration]: configuration [Compatibility Hints]: compatibility hints…
read the full ical4j overview →
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Frequently asked questions
Is apscheduler or ical4j more popular?
apscheduler has 7,678 GitHub stars and ical4j has 841. apscheduler has the larger community by that measure.
Are apscheduler and ical4j free?
Both are open source. apscheduler is licensed under MIT and ical4j under BSD-3-Clause. Neither carries a licence fee.
What is the difference between apscheduler and ical4j?
apscheduler is written in Python and ical4j in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, apscheduler or ical4j?
Choose apscheduler if you want the larger community (7,678 stars) or its MIT licence terms. Choose ical4j if its feature set, stack or BSD-3-Clause licence fits better. Both are self-hostable.