Open Source Calendar Software
Sort By:
Calendar Software
View 112 business solutionsBrowse free open source Calendar software and projects below. Use the toggles on the left to filter open source Calendar software by OS, license, language, programming language, and project status.
-
99.99% Uptime for MySQL and PostgreSQL on Google CloudCloud SQL Enterprise Plus gives you a 99.99% availability SLA with near-zero downtime maintenance—typically under 10 seconds. Get 2x better read/write performance, intelligent data caching, and 35 days of point-in-time recovery. Supports MySQL, PostgreSQL, and SQL Server with built-in vector search for gen AI apps. New customers get $300 in free credit.
-
Cut Data Warehouse Costs up to 54% with BigQueryBigQuery delivers up to 54% lower TCO than cloud alternatives. Migrate from legacy or competing warehouses using free BigQuery Migration Service with automated SQL translation. Get serverless scale with no infrastructure to manage, compressed storage, and flexible pricing—pay per query or commit for deeper discounts. New customers get $300 in free credit.
-
1
Vtiger CRM
An enterprise-class CRM and more!
Vtiger CRM enables sales, support, and marketing teams to organize and collaborate to measurably improve customer experiences and business outcomes. Vtiger CRM also includes email, inventory, project management, and other tools, providing a complete the business management suite. Download Vtiger CRM here or sign up for a free 15-day free trial of the cloud-based application with free updates and support at https://www.vtiger.com/ -
2
Outlook CalDav Synchronizer
Sync Outlook with Google, SOGo or any other CalDAV / CardDAV server
Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google, SOGo, NextCloud, Horde or any other CalDAV or CardDAV server. Supported Outlook versions are 2021, 2019, 2016, 2013, 2010 and 2007 and Office 365 for Desktop. This project was initially developed as a master thesis project at the University of Applied Sciences Technikum Wien, Software Engineering Degree program. Outlook CalDav Synchronizer is Free and Open-Source Software (FOSS), still you can support the project by donating on Sourceforge or directly within the About dialog of our Plugin. Contact us for enterprise support at https://caldavsynchronizer.org/enterprise/contact -
3
Ever wanted to get rid of Outlook ? DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP gateway allowing users to use any mail client with Exchange and Office 365, even from the internet through Outlook Web Access on any platform, tested on MacOSX, Linux and Windows
-
4
Outlook Google Calendar Sync
Sync your Outlook and Google calendars
Offers calendar synchronization between Outlook and Google, including attendees and reminders. Completely free, no install necessary, works behind web proxies and actively developed. Supports all versions of Outlook from 2003 to 2019/Microsoft365 64-bit! Installable and portable options - even runs from a USB thumbdrive. Synchronises items in any calendar folder, including those shared with you. Differential comparison updates only attributes that have changed. Customizable date range to synchronize, past and future. Frequency of automatic syncs, including push-sync from Outlook. Configurable proxy settings, or use Internet Explorer's. Merge new events into existing on the destination calendar. Prompt on deletion of items. Ability to obfuscate custom words for privacy/security. Option to force items as public or private in target calendar. Syncs recurring items properly as a series. -
Deploy Apps in Seconds with Cloud RunCloud Run is the fastest way to deploy containerized apps. Push your code in Go, Python, Node.js, Java, or any language and Cloud Run builds and deploys it automatically. Get fast autoscaling, pay only when your code runs, and skip the infrastructure headaches. Two million requests free per month. And new customers get $300 in free credit.
-
5
Group Office groupware and CRM
Take your office and CRM into the cloud!
Installation instructions can be found here: https://groupoffice.readthedocs.io/en/latest/install/install.html Group Office is an open source groupware application. It makes your daily office tasks easier. Share projects, calendars, files and e-mail online. It is a complete solution for all your online office needs. From a customer phone call to a project and finally an invoice. The support system helps to keep your customers happy. Group Office is fast, secure and has privacy by design. You can stay in full control of your data by self hosting your cloud and e-mail. Our document editing solution keeps all data on the secured server instead of synchronising it to all user devices. GroupOffice is open source and modular. Which means it’s easy to customise and extend. You can turn off and on features and it enables any developer to create new modules for the platform. -
6
FullCalendar
Full-sized drag & drop event calendar
FullCalendar generates real React virtual DOM nodes so you can leverage Fiber, React's highly optimized rendering engine. With over 300 settings, and more being added every release, FullCalendar can do just about anything. Reduce your project's bundle size by using FullCalendar's modular plugins. With over 10 years of open source and over 100 contributors, FullCalendar will always have a free and open source core. Level-up by purchasing premium plugins and support. FullCalendar seamlessly integrates with the React JavaScript framework. It provides a component that exactly matches the functionality of FullCalendar’s standard API. This is more than a mere “connector”. It tells the core FullCalendar package to begin rendering with React virtual DOM nodes as opposed to the Preact nodes it normally uses, transforming FullCalendar into a “real” React component. You can learn a bit more from this blog post (more info to come). -
7
Simple Calendar
A simple calendar with events, customizable widgets and no ads
The most handy calendar out there. Manage your events and reminders easily. Simple Calendar Pro is a really flexible calendar with many event related options. It offers powerful repetition rules, optional CalDAV synchronization, ics file handling and much more. Top notch design ensures the best possible user experience. You will get familiar with it really quickly. You can create new events really quickly by predefining default values, or by duplicating existing events. There are many views you can choose from, depending on your preference. No matter if you want to see just 1 day or 1 year, this app supports it. Personalize your experience by changing any app color. You can even change the apps' icon color to make sure it matches your home screen. The Pro one already has many new features including time zone support, attendees and email type of reminders in CalDAV synced events, then many other bugfixes and stability improvements. -
8
bootstrap-datepicker
A datepicker for twitter bootstrap
Bootstrap-datepicker provides a flexible datepicker widget in the Bootstrap style. Versions are incremented according to semver. As with bootstrap’s own plugins, datepicker provides a data-api that can be used to instantiate datepickers without the need for custom javascript. You can disable datepicker’s data-api in the same way as you would disable other bootstrap plugins. Most options can be provided via data-attributes. An option can be converted to a data-attribute by taking its name, replacing each uppercase letter with its lowercase equivalent preceded by a dash, and prepending “data-date-” to the result. Methods are called on a datepicker by calling the datepicker function with a string first argument, followed by any arguments the method takes. -
9
Project has moved to github: https://github.com/craigk5n/webcalendar WebCalendar is a PHP application used to maintain a calendar for a single user or an intranet group of users. It can also be configured as an event calendar.
-
Our Free Plans just got better! | Auth0You asked, we delivered! Auth0 is excited to expand our Free and Paid plans to include more options so you can focus on building, deploying, and scaling applications without having to worry about your security. Auth0 now, thank yourself later.
-
10
Hero Planner
An easy to use GUI for creating team rotas and scheduling absences.
HERO Planner – Unleash Your Scheduling Superpowers Is rostering your kryptonite? Transform chaos into control with HERO Planner, the command center for retail, hospitality, and service teams. This modern desktop app turns managers into scheduling superheroes—no cape required. Your Utility Belt: ✓ Super Speed: Intuitive drag-and-drop & bulk actions for lightning-fast updates. ✓ Compliance Shield: Real-time alerts guard against labour law violations and overtime risks. ✓ X-Ray Vision: Instantly visualize coverage gaps, conflicts, and staff availability. ✓ Universal Export: PDF, CSV, and HTML formats. ✓ Stealth Mode: Sleek Dark Mode & customizable themes. Built on Electron, React & Vite for blazing performance. Whether managing a small squad or a legion of 200+ staff, HERO Planner gives you the tools to save the day. Don't just manage the rota—be the Hero. -
11
WeekToDo
WeekToDo is a Free and Open Source Minimalist Weekly Planner
WeekToDo is a free minimalist weekly planner app focused on privacy. Schedule your tasks and projects with to-do lists and a calendar. Available for Windows, Mac, Linux or online. WeekToDo is a free and Open Source minimalist weekly planner. With WeekToDo you can start improving your productivity by defining and managing your week and your tasks in an easy and intuitive way. WeekToDo mixes the concept of a calendar and tasks list in a single interface. You can set alarms, colors, recurrent tasks, subtasks, and all this in an intuitive and easy way. Also, we care about your privacy so all your data is stored in your device. WeekToDo is a free and Open Source project available for everyone. You can enjoy it like a native app on Windows, macOS, and Linux or directly from your web browser. It is also available in multiple languages. -
12
openjardin
A software for the management of a permaculture oriented garden.
Une nouvelle version quickjardinV6 est disponible pour mac jusque macos10.15 et linux .deb validé sur Kunbutu 22.04 . elle utilse QML pour plus de rapidité. Openjardin is a free software GNU gpl 3.0 for the management of a permaculture oriented garden. (Français-Italiano-English) It allows interactive management of crop plots, with annual planning and crop rotation . Le logiciel Open jardin est destiné à la gestion des cultures d'un jardin à partir d'un plan avec la représentation de parcelles, de fiches de cultures, d'un tableau du planning annuel par parcelle, et d'un tableau des rotations de cultures sur 5 ans pour chaque parcelle avec la visualisation des cultures précédentes colorées selon la famille botanique. -
13
!!We've Moved to GitHub at http://github.com/libical !!The code here on SourceForge is frozen !!Please follow us at http://libical.github.io/libical The Free Association project maintains libical, an open source reference implementation of the icalendar data type and serialization format. libical is used in dozens of calendaring and scheduling products.
-
14
RedNotebook is a graphical diary and journal helping you to keep track of notes and thoughts. It includes a calendar navigation, customizable templates for each day, export functionality and word clouds. You can also format, tag and search your entries. Please find the latest releases at https://rednotebook.app
-
15
Osmo is a handy personal organizer, which includes calendar, tasks manager, address book and notes modules. It was designed to be a small, easy to use and good looking PIM tool to help to manage personal information.
-
16
Etar Calendar
Android open source calendar
Etar is an open-source material-designed calendar made for everyone. -
17
react-big-calendar
gcal/outlook like calendar component
An events calendar component built for React and made for modern browsers (read: IE10+) and uses flexbox over the classic tables-ception approach. Styles can be found at: react-big-calendar/lib/css/react-big-calendar.css, and should be included on the page with the calendar component. Also make sure that your calendar's container element has a height, or the calendar won't be visible. Date internationalization and localization is hard and react-big-calendar doesn't even attempt to solve that problem. Instead you can use one of the many excellent solutions already out there, via adapters called "localizers". Big Calendar comes with two localizers for use with Globalize.js or Moment.js. Choose the localizer that best suits your needs, or write your own. Whatever you do, you'll need to set it up before you can use the calendar (you only need to set it up once). -
18
Zentyal, Linux Small Business Server
Zentyal is a Linux Small Business Server
Zentyal Server is an easy to use and affordable Linux server, specially designed to meet the needs of small and medium businesses Thanks to Zentyal's Samba integration, Zentyal provides native compatibility with Microsoft Active Directory, allowing you to join Microsoft clients to a domain and manage them easily. Zentyal Server incorporates all the network services required in a small and medium business environment: * Directory & Domain Server with native compatibility with Microsoft Active Directory * Mail Server with ActiveSync and webmail * Gateway with firewall and proxy * Infrastructure Server with DNS/DHCP server, Certification Authority and Virtual Private Networks For more information and download, please access the project's home page. -
19
FMA is a SMS Manager, Mobile Phone Monitor, Remote Control Agent, Phonebook Manager, Organizer, Fun and much more; whatever you want it to be, it is whatever a mobile phone should have :-) (Currently based on Sony Ericsson features set).
-
20
Defalto
Fast, modular open-source CRM for growing businesses
Defalto CRM, developed by IT-Solutions4You, is a modern and modular open-source CRM system built on over 15 years of real business and CRM development experience. Designed for companies of all sizes, it helps teams manage sales, projects, and customer relationships efficiently through a clean, intuitive interface. The platform combines professional know-how with modern design and functionality. Its free core modules cover essential CRM features, while optional add-ons expand capabilities for advanced business needs. Defalto CRM supports both on-premise and cloud deployment, offering full flexibility and data control. Source code available at: https://github.com/IT-Solutions4You/defalto -
21
qOrganizer is a general organizer that includes a calendar with schedule,reminders,journal/notes for every day, to-do list.But provides features useful for students such as:timetable and a booklet for marks and absences.It's designed to be easy to use.
-
22
Java-Kalender
Platformunabhängiger Kalender zum Eintragen von Ereignissen
Platformunabhängiger Kalender zum Eintragen von Ereignissen mit Erinnerungsfunktion. Beinhaltet alle deutschen Feiertage. Zwischen den Ansichten Jahresansicht, Monatsansicht, Wochenansicht und Tagesansicht kann umgeschaltet werden. Der Kalender kann im Hintergrund laufen und ist personalisierbar. Automatische Erinnerungsfunktion für nahende Ereignisse / Feiertage. Synchronisation über einen FTP-Server möglich. -
23
Manage events on a Google Calendar
Manage events on a Google Calendar
This package makes working with a Google Calendar a breeze. Manage events on a Google Calendar. The first thing you’ll need to do is get credentials to use Google's API. I’m assuming that you’ve already created a Google account and are signed in. Head over to Google API console and click "Select a project" in the header. You can give the service account a name. You can name it anything you’d like. In the service account id you’ll see an email address. We’ll use this email address later on in this guide. Select "JSON" as the key type and click "Create" to download the JSON file. You will get a warning that the service account does not have a role, you can safely ignore this and create the service account without assigning a role. Head over to Google Calendar and view the settings of the calendar you want to work with via PHP. On the "Share with specific people" tab press the "Add people" button and add the service account id that was displayed when creating credentials on the API site. -
24
Tempus Dominus
A date/time picker widget
Tempus Dominus is the successor to the very popular "eonasdan/bootstrap-datetimepicker". The plugin provide a robust date and time picker designed to integrate into your project. The picker uses the format option to decide what components to show. Set format to LT, LTS or another valid MomentJs format string to display certain components. The picker uses MomentJs to determine the language string. You can use moment-with-locales or you can include whatever local file you need. Start of the week is based on the locale provided. This is defined by moment's locales. If you want to change it, create your own locale file or override. Looking for a template with the datepicker ready to go? Then get check out the templates provided in our website. Bootstrap.js is needed (transition and collapse are required if you're not using the full Bootstrap). -
25
JDavide (per gli amici JD) è un software gratuito per la gestione dello Studio Legale che aiuta l’avvocato nell’espletamento delle operazioni quotidiane. Funzionalità: pratiche, agenda, formulario, atti, parcellazione, rivalutazione, ecc.
