Open Source Calendar Software
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Calendar Software
View 123 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.
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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/ -
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DavMail is a POP/IMAP/SMTP/CalDAV/CardDAV/LDAP Exchange and Office 365 gateway allowing users to use any mail/calendar client (e.g. Thunderbird with Lightning or Apple iCal) with an Exchange server. DavMail now includes an LDAP gateway to Exchange global address book and user personal contacts to allow recipient address completion in the mail compose window and full calendar support with attendee free busy display. The main goal of DavMail is to provide standard compliant protocols in front of proprietary Exchange. This means LDAP for address book search, SMTP to send messages, IMAP to browse messages on the server in any folder, POP to retrieve inbox messages only, CalDAV for calendar support and CardDAV for contact synchronization.
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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 -
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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. -
Go from Code to Production URL in SecondsSkip the Kubernetes configs. Cloud Run handles HTTPS, scaling, and infrastructure automatically. Two million requests free per month.
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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). -
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!!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.
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Etar Calendar
Android open source calendar
Etar is an open-source material-designed calendar made for everyone. -
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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
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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.
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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).
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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). -
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RemoteCalendars is a COM-.NET Add-in for Outlook 2003/2007, written in C#. After installing this plugin, every Outlook user should be able to subscribe, reload and delete a generic remote iCalendar (RFC 2445) from Outlook 2003/2007.
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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. -
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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. -
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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.
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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. -
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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.
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Cal.com
Scheduling infrastructure for absolutely everyone
Meet Cal.com, the event-juggling scheduler for everyone. Focus on meetings, not making meetings. Free for individuals. Cal reads your availability from all your existing calendars ensuring you never get double booked! Set repeating schedules for the times of the day and week that you want people to be able to book you. Share your short cal.com personal link and make it incredibly easy for people to book a meeting at a time that works for both of you! Set availability, location, duration and more on a per-link basis. Send bookings to different calendars or set a default. Cal.com checks for conflicts across all of your calendars and only offers times that are open. Never get double-booked again. Cal.com enables you to build processes around your events. Notifications, reminders, and follow-ups are automatically taken care of. -
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Cal.diy
Scheduling infrastructure for absolutely everyone
The Cal.diy project is a fully open-source, self-hosted scheduling platform that provides an alternative to proprietary booking tools while giving users complete control over their infrastructure. It is a community-driven fork of Cal.com that removes all enterprise and commercial features, ensuring that the entire codebase remains MIT-licensed and accessible. The platform enables users to manage bookings, availability, and integrations without relying on external services or subscription models. Built with modern web technologies such as Next.js, React, and PostgreSQL, it offers a robust foundation for building custom scheduling workflows. The system is designed for developers and advanced users who prefer to host and secure their own data rather than depend on third-party providers. It also supports integration with external tools through APIs and authentication systems, allowing flexible customization. -
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Joda-Time
Replacement for the Java date and time classes prior to Java SE 8
The standard date and time classes prior to Java SE 8 are poor. By tackling this problem head-on, Joda-Time became the de facto standard date and time library for Java prior to Java SE 8. Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project. The design allows for multiple calendar systems, while still providing a simple API. The “default” calendar is the ISO8601 standard which is used by many other standards. The Gregorian, Julian, Buddhist, Coptic, Ethiopic and Islamic calendar systems are also included. Supporting classes include time zone, duration, format and parsing. Joda-Time provides a quality replacement for the Java date and time classes. Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310). -
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React Infinite Calendar
Infinite scrolling date-picker built with React
The React Infinite Calendar project is a highly customizable date picker component for React applications that leverages virtualized rendering to provide smooth infinite scrolling through dates. It is designed to handle large date ranges efficiently by rendering only visible elements, which significantly improves performance compared to traditional calendar components. The library supports features such as localization, theming, keyboard navigation, and flexible date constraints, making it suitable for a wide variety of use cases. It integrates seamlessly with modern React workflows and supports multiple module formats for easy adoption in different environments. The component also includes advanced display options such as overlays, animations, and helper elements to enhance user experience. Its architecture relies on virtualization techniques to maintain responsiveness even when navigating across decades of dates. -
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Lifeograph
Cross-platform, parametric note-taking application
Lifeograph combines powerful features with a clean and thoughtfully designed interface. Your data stays on your device, and built-in encryption keeps privacy at the core. With WYSIWYG editing, your entries always appear in their final form. Integrated data extraction tools transform your journal entries into dynamic tables and charts. -
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Date Picker Calendar LibreOffice Calc
Date Picker Calendar extension for LibreOffice Calc
Date Picker Calendar (Latest version 2.60) Set a date in selected cell/cells. Creates a calendar push button in the selected cell and places the date in the cell next to the button. All functions are also in the menu: Tools - Add-Ons. It is possible to change certain settings via the 'Settings' button on the help screen. Calendar Help is located in the help menu of LibreOffice. Toolbar buttons: - Date: the date from the calendar will be inserted in the selected cell/cells. - Date <-Button: a calendar button is created in the selected cell, the date is inserted in the cell to the left of the button. - Button-> Date: a calendar button is created in the selected cell, the date is inserted in the cell to the right of the button. -
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Date Picker Calendar OpenOffice Calc
Date Picker Calendar extension for OpenOffice Calc
Date Picker Calendar (Latest version 2.60) Set a date in selected cell/cells. Creates a calendar push button in the selected cell and places the date in the cell next to the button. All functions are also in the menu: Tools - Add-Ons. It is possible to change certain settings via the 'Settings' button on the help screen. Calendar Help is located in the help menu of OpenOffice. Toolbar buttons: - Date: the date from the calendar will be inserted in the selected cell/cells. - Date <-Button: a calendar button is created in the selected cell, the date is inserted in the cell to the left of the button. - Button-> Date: a calendar button is created in the selected cell, the date is inserted in the cell to the right of the button. -
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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.
