Open-source TidyCal alternatives

Cal.diy is a community edition of Cal.com, the scheduling platform, released as open source. It is a fork with all enterprise and commercial code removed, and the whole codebase is licensed under MIT with no proprietary Enterprise Edition split. It is built with TypeScript, Next.js, tRPC, Tailwind CSS and PostgreSQL through Prisma.

Compared with Cal.com, it drops enterprise features such as Teams, Organizations, Insights, Workflows and SSO/SAML, and it needs no license key or Cal.com account. Contributions go directly into this community-maintained project. No hosted service exists, so you run it yourself on infrastructure you control.

The maintainers warn that it is intended for personal, non-production use and that running it yourself demands solid skills in server administration, databases and protecting sensitive data. For commercial or enterprise needs they point to Cal.com instead. Cal.diy suits individuals and tinkerers who want complete control over their own scheduling setup.

Easy!Appointments is an open-source appointment scheduling system that lets you run your own booking workflow. It is self-hosted, so your data stays under your control, and it can be customized and integrated with an existing website and database.

Features include appointment and customer management, organization of services and providers, working plans and booking rules, Google Calendar synchronization, an email notification system and a multi-language interface. Topics on the repository also point to a REST API for integrations.

Production installs need Apache or Nginx, PHP 8.2 or later and a MySQL database: upload the files, create the database, copy config-sample.php to config.php and update the settings. A Docker Compose environment is provided for development. It is licensed under GPL-3.0, free for personal and commercial use, with premium features and professional services offered separately.

Thunderbird Appointment is an open-source scheduling tool for inviting others to grab times on your calendar. The goal is to make booking appointments as easy as possible: you set your availability, share a link, and attendees pick a slot on a bookers page. It is part of the Thunderbird Pro family of services.

Subscribers get a dashboard for setting up availability, managing bookings and adjusting general settings. The supported way to build and run it is with Docker, which starts five containers: the backend, the frontend, PostgreSQL, Redis and Mailpit for testing email, with OpenAPI documentation available from the backend. A flag controls whether first-time registration is allowed to create the initial admin user, and an allow list defines admin accounts. Simple password-based authentication is meant only for development and testing.

The backend is written in Python and the project is licensed under MPL-2.0. A hosted service is available at appointment.tb.pro, and feedback and support are handled through a mailing list called Topicbox.

Someday is a simple open-source scheduling tool designed for people who use Gmail. It lets visitors pick an open slot from your calendar availability, and it is positioned as an alternative to Calendly and Cal.com. It runs as a Google Apps Script, so hosting is free through your own Google account, and the clasp tool is used to deploy it.

You set your working hours by editing variables in the backend source. Visitors choose a date and time slot, then fill in a short form with name, email, phone number and an optional note. The front end is built with React, TypeScript, shadcn/ui and Vite. The README says no data is shared with third-party apps beyond Google.

Apps Script shows a banner saying the page was created by a Google Apps Script user. The README explains how to remove it by hosting the HTML yourself, for example on GitHub Pages, and embedding the script in an iframe. A demo with mocked endpoints is available, and the project is MIT licensed.