Table of Content
Calendar is an app that is used on daily basis, it is a significant tool for organization, planning, daily routine tasks, appointments management, and personal improvements.
As an example, Google Calendar is a scheduling calendar service by Google. It aids users in creating events, tasks, schedule and managing appointments, and keeping everything in sync and stored on the cloud. It also allows users to share events, attach locations, and more.
The primary problem is: it requires an internet connection.
In this article, we provide you with a collection of desktop calendar apps, that will help you to organize your events, deal with calendar files and keep track of your tasks and daily routines.
1- Thunderbird Calendar
Thunderbird is a free email client by Mozilla. It is the open-source counterpart for Microsoft Outlook. It supports plugins and add-ons which charge it with features to the next level.
With the Lighting Calendar add-on, the user can organize their events, schedules, and tasks.
Although Thunderbird is not a priority for Mozilla at the moment, it still has many loyal users.
Platforms: macOS, Windows, and Linux.
Calendar
Organize your life — it’s about time!
Thunderbird
2- Evolution
Evolution is a free open-source personal information system with an integrated email client, calendar, and address book. Evolution is the open-source Microsoft Outlook alternative for Linux desktops.
Platforms: Linux (Gnome Desktops).
Evolution Mail and Calendar
Written By Phil Bull
Andre Klapper
3- Borg Calendar
Borg Calendar is a cross-platform desktop calendar and task tracking management program.
Borg Calendar features a built-in view switcher, to-do list, pop-up reminders, checklist, a lightweight project management system, XML import/ export, a simple address book, and more.
The system also can be used to save private memos and secure information like passwords and such with strong encryption support.
Platforms: Windows, Linux, and macOS.
GitHub — mikeberger/borg_calendar: BORG Calendar — A Desktop Calendar and Task Tracking System. Language: Java Swing
BORG Calendar — A Desktop Calendar and Task Tracking System. Language: Java Swing — GitHub — mikeberger/borg_calendar: BORG Calendar — A Desktop Calendar and Task Tracking System. Language: Java Swing
GitHubmikeberger
4- k5ncal
k5ncal is a standard-based multi-user calendar application with full support for (iCalendar). It supports advanced recurrence rules, event editing, and more.
k5ncal is released under GNU GPL license and requires Java 1.8 or later.
Platforms: Windows, macOS, and Linux.
GitHub — craigk5n/k5ncal: Java-based calendar application that leverages existing standards (iCalendar) to create an open source cross-platform multi-user desktop calendar application.
Java-based calendar application that leverages existing standards (iCalendar) to create an open source cross-platform multi-user desktop calendar application. — GitHub — craigk5n/k5ncal: Java-base…
GitHubcraigk5n
5- WLCalendarGadget (Windows)
WLCalendar is a free lightweight calendar app for Windows systems. It supports Windows Vista, 8, and 10. It works smoothly offline, supports multiple themes, system notification, and is translated into 9 languages.
WLCalendar is coming with multiple calendar support alongside running multiple app instances, which means it can manage many personal and work calendars at once.
WLCalendar works smoothly with Outlook Live Calendar, .ics files, Google Calendar, and other calendar apps.
Platforms: Windows.
GitHub — poulicek/WLCalendarGadget: Desktop gadget for Windows showing calendar with events from iCalendar feeds
Desktop gadget for Windows showing calendar with events from iCalendar feeds — GitHub — poulicek/WLCalendarGadget: Desktop gadget for Windows showing calendar with events from iCalendar feeds
GitHubpoulicek
6- OSMO (Linux)
OSMO has been my favorite calendar application on Linux for years, mainly because it helps me manage my notes, schedule, contacts, and tasks.
OSMO features a compact user interface, rich calendar features, event notes, full calendar integration with tasks and contact modules, and full-search support for all modules.
With OSMO, you can have iCalendar import and export as well as contact export in CSV and XHTML.
OSMO works on all popular Linux and UNIX systems like Ubuntu, Arch Linux, Debian, Fedora, Linux Mint, Slackware, Gentoo, PuppyLinux, OpenSUSE, Manjaro, FreeBSD, OpenBSD, and MX Linux.
- Platforms: Linux.
Osmo (PIM)
7- Deskcall
Deskcall is a free, open-source cross-platform desktop client for Google Calendar. It is built with Electron and released under GPL-3.0.
Platforms: Windows, macOS, and Linux.
GitHub — cognophile/Deskcal: An unofficial cross-platform desktop Google Calendar application.
An unofficial cross-platform desktop Google Calendar application. — GitHub — cognophile/Deskcal: An unofficial cross-platform desktop Google Calendar application.
GitHubcognophile
8- Day Planner
Day Planner is a simple, lightweight open-source calendar app for Linux systems. It offers full support for iCalendar format, data synchronization with its own server, multilingual interface, and system notification.
Platforms: Linux.
Day Planner — Download
Day Planner is a free software day planner and reminder for GNU/Linux and other Unix-like operating systems
Download
9- qOrganizer
qOrganizer is an open-source general organizer for helping active people manage their tasks, timetable, events, notes, reminders, journals on a daily basis.
qOrganizer features include rich text mode for journal editing, sound reminders, image attachment, local SQLite database with remote MySQL database support, and a multilingual interface (translated to 14 languages).
Although the app has not been updated for 10 years, it is getting active downloads every week.
Platforms: Linux and Windows.
qOrganizer official website
10- KABE-Calendar
KABE Calendar is a simple, free Windows Calendar app written in Delphi/ Kylix language. It is released under BSD License and LGPLv2.
Platforms: Windows.
KABE-Calendar
Download KABE-Calendar for free. The “KABE-Calendar” is “free desktop calendar software” such as “wall hangings calendar”. to display for up to one year.
SourceForge
11- BSplanner
BSplanner is a cross-platform open-source calendar app to manage daily, weekly, monthly activities. It is released under GPLv2.
Platforms: Windows, Linux, and macOS.
BSPlanner
Download BSPlanner for free. Organize your activities with the help of this software. BSplanner is a simple, easy to use calendar application designed to lend you a hand when it comes to managing your daily or monthly activities.
SourceForge
12- Stategr
Stategr App is a macOS time organizer app with rich calendar options for macOS and Windows.
Stategr helps users to boost their productivity by managing their time sessions, activities, tasks, and appointments in a simple productive interface.
Stategr features iCalendar import and export, dark theme, rich shortcuts and hotkeys set, and color-coded lists.
The app is written with C++ language and works on macOS and Windows. The developer is working now on an iOS version.
Stategr is released as an open-source project under GPLv3.
Platforms: Windows, and macOS.
Strategr — Time Management App
Strategr — Time Management App
StrategrDmitry Khrykin
13- Itsycal (macOS)
Itsycal is a small, lightweight menubar calendar application for macOS. It is released under the MIT license.
Itsycal comes with a simple yet powerful user interface to aid in quick access to events, calendar, upcoming events, and planning future events.
GitHub — sfsam/Itsycal: Itsycal is a tiny calendar for your Mac’s menu bar. http://www.mowglii.com/itsycal
Itsycal is a tiny calendar for your Mac’s menu bar. http://www.mowglii.com/itsycal — GitHub — sfsam/Itsycal: Itsycal is a tiny calendar for your Mac’s menu bar. http://www.mowglii.com/itsycal
GitHubsfsam
14- CornerCal (macOS)
CornerCal is an open-source, free menubar calendar application for macOS. Although it is inspired by Itsycal, it has a different unique interface and approach.
CornerCal is released under MIT License and supports macOS Sierra 10.12 and higher.
GitHub — ekreutz/CornerCal: A simple, clean calendar and clock app for macOS.
A simple, clean calendar and clock app for macOS. Contribute to ekreutz/CornerCal development by creating an account on GitHub.
GitHubekreutz
15- Up Next (macOS)
Up Next is yet another small menubar calendar app for macOS. It helps you effortlessly to manage your meetings without a complex setup.
Up Next features quick access (hotkey) to add and edit meetings and event sync.
GitHub — upnextinc/upnext: 📆 See/join meetings from the menu bar
📆 See/join meetings from the menu bar. Contribute to upnextinc/upnext development by creating an account on GitHub.
GitHubupnextinc
16- MeetingBar (macOS)
MeetingBar is a free open-source lightweight menubar app for macOS to keep track of meetings.
MeetingBar shows all of your upcoming meetings, allows you to bookmark your important and favorite meetings, and mark events with specific services like Zoom, Google Meetings, MS Teams, Skype, or others.
You can use MeetingBar with any other calendar application as a meeting and appointment schedule system without the need to access your calendar app.
GitHub — leits/MeetingBar: 🇺🇦 Your meetings at your fingertips in the macOS menu bar
🇺🇦 Your meetings at your fingertips in the macOS menu bar — GitHub — leits/MeetingBar: 🇺🇦 Your meetings at your fingertips in the macOS menu bar
GitHubleits
17- Desktop Calendar
Desktop Calendar is a free (not open-source) rich calendar application for Windows, macOS, iOS, and Android.
It features appointments, tasks, events, schedules management, and more.
Platforms: Windows, macOS, Android, and iOS.
Desktop Calendar
Desktop Calendar is a cool calendar placed on your windows desktop. Record anything by double-click on desktop. It’s very convenient and useful. Desktop Calendar will help you manage appointments, to-do lists, schedules, and more… And, Desktop Calendar also offers a variety of common festivals, an…
DesktopCal, Inc.
18- Calcurse (Command-line/ Terminal)
Calcurse is a feature-rich, beautiful command-line calendar application that uses the curses-UI library.
Calcurse supports iCalendar import and export, CalDAV sync, UTF-8 support, hooks, and modified scripts support, and a built-in notification system.
calcurse: a text-based calendar and scheduling application
19- Khal (CLI)
Khal is a CLI/ Terminal calendar application that offers sync to CalDAV servers.
Khal is released under Expat/ MIT license.
GitHub — pimutils/khal: :calendar: CLI calendar application
:calendar: CLI calendar application. Contribute to pimutils/khal development by creating an account on GitHub.
GitHubpimutils
20- California Gnome 3.0 Calendar
California is an open-source Linux Calendar app for Gnome 3.0 desktops.
California can be installed on Ubuntu, Debian, Arch Linux, Manjaro, LinuxMint, MX Linux, Fedora, and RedHat Linux.
Apps/California — GNOME Wiki!
GNOME Wiki!
21- norcal (CLI)
norcal is a command-line calendar application written in Node.js and released under the BSD license.
norcal allows you to add, view, list, remove, and query events with simple memorable commands.
norcal is no longer available.
22- KOrganizer
KOrganizer is a rich calendar application for KDE (Linux/ UNIX) desktops. It features multiple calendar support, unlimited to-do lists, file attachments, and printing support.
KOrganizer is a part of KDE applications, and it is released under GPL-20+ License.
Platforms: Linux (KDE desktops).
KOrganizer
KOrganizer is a calendar and scheduling application
KDE Applications
23- RainLendar
RainLendar is a free customizable calendar application for managing events, appointments, tasks, and meetings.
It features events management, schedule creation, system alarm, iCalendar format support (RFC2445), multilingual support,
Platforms: Windows, Linux, and macOS.
Rainlendar
24- Focal
Focal is a calendar application for Linux with CalDAV support. It is released under GPL v3.0 License.
Focal is designed to work with CalDAV servers as SabreDAV, Apple Calendar, Radicale, and others.
- Platform: Linux.
GitHub — ohwgiles/focal: Calendar application for Linux with CalDAV
Calendar application for Linux with CalDAV. Contribute to ohwgiles/focal development by creating an account on GitHub.
GitHubohwgiles
25- OneCalendar
OneCalendar is a rich calendar app for Windows, macOS, and Android systems. It comes with a beautiful user interface, personalized themes, configurable widgets, and built-in dark mode support.
It works seamlessly with all other calendar apps like Google Calendar, Outlook, Office 369, Nextcloud, ownCloud, CalDAV, iCloud, and GMX calendars.
OneCalendar features multiple views, full-text search, events sharing, and multiple languages support.
However, OneCalendar is not an open-source program, however it is totally free to download and use.
Platforms: Windows, macOS, Android.
OneCalendar — Discover the best calendar app of 2023
Get organised! Always have a clear overview of all your appointments everywhere you go.
OneCalendarJeffrey
26- Java-Kalender
Java Kalender is worth noting here because it is a cross-platform calendar app for Windows, macOS, and Linux.
However, it supports mainly Dutch so far.
- Platforms: Windows, and Linux.
Java-Kalender
Download Java-Kalender for free. Platformunabhängiger Kalender zum Eintragen von Ereignissen. Platformunabhängiger Kalender zum Eintragen von Ereignissen mit Erinnerungsfunktion. Beinhaltet alle deutschen Feiertage.
SourceForge
Final Thought
There is no doubt that calendar apps are a significant productivity-boosting tool, which is used for work, organizing meetings, personal development, and more.
We hope that our collection will aid anyone who is looking for open-source, free-to-use Calendar apps.
If you know of any other open-source calendar app for Linux, Windows, or macOS, that we missed, please send it to us, and we will gladly add it here.
Here is a list of best free open source calendar software for Windows. These are free desktop calendar software which come with open source license. You can freely download and study source code of these calendar software and even manipulate the source code.
These calendar software let you view the calendar in monthly, daily, weekly, or yearly view. You can also add and schedule important events on particular dates in a month. All of these software provide appointment editor tool to add and manage multiple appointments with date and time, reminder settings, priority, etc. You also get a feature to add and manage various contacts in a few of these software. Additionally, you can create a to-do list in these software to keep up with your daily tasks. You can also add essential notes and memos on particular dates.
In one of these software, you can also import iCalendar files to add calendar events. Also, for students, there is a nice software with features including time table and booklet creator. Other than that, you get various useful features in these software which include task categories creator, email alert generator, setup calendar appearance, reminder tone, etc. In general, these are featured open source calendar software which are useful in keeping up with the dates and managing important tasks.
My favorite Free Open Source Calendar Software for Windows:
BORG Calendar is a good desktop calendar software which comes with a lot of handy tools including appointment editor, tasks creator, memos creator, checklists maker, etc.
qOrganizer is another nice open source calendar software which provides two unique features which are helpful for students. Those features are Time Table Maker and Booklet Maker (with subject marks and absences).
You may also like some best free Holiday Calendar Software, Portable Diary Software, and Open Source Journal Software for Windows.
BORG Calendar
BORG Calendar is a free open source calendar software for Windows. It is a great desktop calendar which shows the current month and highlights important dates and occasion. You can move to previous or next month in the calendar easily. Besides that, it also lets you add and manage events on particular days of a month. Other than that, it comes with a variety of features that you can look forward to.
Main Features of this Open Source Calendar Software:
- You get different views to open and view calendar including Day, Week, Month, and Year views.
- It provides an appointment editor using which you can add appointments or other events on a date of the month. In the appointment editor, you get options to customize appointments using options like appointment time, category and other properties (to do, holiday, private, etc.), send reminder email, link files, add URL, priority, popup reminders, etc.
- It also provides an option to encrypt an appointment.
- It provides separate tabs to create Memos, Tasks, Todo, Checklists, etc.
- It lets you add and edit different categories to manage various distinguished tasks.
- You get a search feature in it to find a specific task, memo, appointment, etc.
- It lets you edit various program specific preferences including appearance, font, email parameters (SMTP server, SMTP port, reminder email time, etc.), popup reminders, color schemes, Todo options, etc.
- It provides an Address Book to store various contacts and addresses with information like first name, last name, home address, contact number, etc.
- You can import iCalendar (ICAL) files from PC or by using URL to import calendar tasks to this software. It also lets you export your monthly events and tasks to the same ICAL file.
- It contains a CALDAV sync feature too.
Conclusion:
BORG Calendar is one of the best free open source calendar software. It contains all those features which you look forward in a desktop calendar including appointment, events, and daily tasks management.
qOrganizer
qOrganizer is another free open source calendar software for Windows. It lets you view calendar and manage your daily events and schedules. Let’s checkout a sorted list of features which are provided in it.
Main Features:
- It lets you schedule several events for a particular date with reminder.
- You can add important notes on any of the dates.
- A To-do List feature is provided in it to add multiple tasks with deadline, priority, and its progress.
- It supports multiple storing modes including text files, SQLite database, and MySQL database.
- You can print the current calendar view, task view, events, or any other page.
- It lets you set up general settings such as FTP server, language, reminder type, date format, play sound, etc.
Additional Features:
It provides two handy options which are useful for students:
- You can also create your weekly time table in this calendar software.
- It lets you create and manage a booklet with subjects’ marks and absences.
Conclusion:
It is a great open source calendar software with some unique and useful features. Students might like to checkout this desktop calendar.
KABE-Calendar
KABE-Calendar is yet another open source calendar software for Windows. It’s like a wall hanging calendar which you can place anywhere on your desktop screen.
Main Features:
- You can add events on a particular date with name, color, popup time, etc.
- It also lets you add memos on specific dates.
- You can also setup tasks with begin day, end day, completion day, color, name, and pop up time.
- Regular events in month, business day, every week, holiday, etc., can also be added in it.
- You can also manually add memorial days to your calendar.
- You can quickly move to previous or next year calendar when needed.
- It lets you view a list of weekly events and a monthly report.
- You can also load event data from CSV files.
- Furthermore, it lets you setup a lot of preferences to customize your calendar including display, font, public holiday, automatic data deletion option, etc.
Conclusion:
KABE-Calendar is another nice open source calendar software which you can use to manage monthly events and tasks.
CSC Calendar
CSC Calendar is yet another open source calendar software for Windows, Mac, and Linux. It is a Java based software, hence you need to have Java installed on your system. It is a portable calendar software which requires no installation and can be used on the go.
Main Features of this Portable Open Source Calendar Software:
- It lets you add appointments on a particular date of the month. You can add appointments with title, location, start time, end time, and notes.
- You can create and manage multiple contacts in it to add them to specific appointments.
- You can view all added appointments which can be edited or deleted, as needed.
Conclusion:
It is a basic but useful calendar software using which you can manage monthly appointments.
BSPlanner
BSPlanner is the next free open source calendar software for Windows. It is a nice and clean desktop calendar which shows monthly calendar.
Main Features:
- You can add events on a particular date at specific time.
- To add an event, you can add information like start time, end time, description, repeat, reminder, etc.
- It lets you add multiple categories to distinguish between different types of tasks.
- You can set different colors for each category.
- Some general preferences can also be set in it like reminder tone, calendar view (monthly, weekly, 4 days, daily, events), date format, etc.
Conclusion:
It is a simple calendar software with all essential calendar features.
For many of us, our calendar is our lifeblood. While some people can get away with a wall calendar or a paper day planner to organize their schedule, a whole lot of us have turned the process of managing time allotments over to a digital calendar.
Most of the major vendor ecosystems provide some sort of calendaring solution which can sync across devices. Among them, Google Calendar is perhaps the most prevalent. For many people, it just works, making it easy to keep track of their schedule across multiple computer and mobile devices, and to share appropriate information with others with whom they need to coordinate.
As with countless other tools, though, you don’t have to use a proprietary hosted solution for your calendar needs. There might just be an open source project that works for you. But before we dive in, let’s take a look at what a calendar actually is.
Internet Calendaring and Scheduling
If you are using a tool like Google Calendar, you’re actually using two separate tools: a user interface (the website or mobile app) and a calendaring server. The calendaring server generates events, accepts invites, and sends reminders to you when something you have scheduled is about to happen.
An event in the iCalendar format (no relation to Apple’s iCal application) is a simple text file. It’s a surprisingly simple format. Here’s an example of a basic event:
BEGIN:VCALENDAR
PRODID:Seth
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VEVENT
CREATED:20200511T114136
DTSTAMP:20200511T114136
LAST-MODIFIED:20200511T114136
UID:VE3HK1CEFCK7O7HUSNUM8X
SUMMARY:Example event
CLASS:PUBLIC
STATUS:CONFIRMED
DESCRIPTION:This is an example ICS file.
DTSTART:20200520T200000Z
DTEND:20200520T203000Z
END:VEVENT
END:VCALENDARIf you copy and paste that text into a file ending in .ics, you can import it into your calendar and it will appear on your schedule. A good calendar app automates that process so you’re rarely aware that it’s happening, but that’s really all there is to the apparent magic of sharing calendars.
It’s not uncommon to receive an .ics file in an email inviting you to an event or meeting. If your email client doesn’t manage this format automatically for you, then you can download and import it into your calendaring application of choice. You can even let other people view and edit your appointments by running a CalDAV server, which is an extension of WebDAV, a protocol for making edits of remote files across HTTP.
Knowing how the tasks are divided, you must decide what functionality is essential to you. If you’re just looking for a quick and easy way to share calendar events with others, then all you really need is an iCalendar-compliant calendaring application. If you want to allow others to view and edit your calendar, then you need a CalDAV service as well.
Nextcloud (Desktop, Web)
Nextcloud is your home away from home, or at least your workspace away from your desk. It’s your own personal cloud storage, text editor, photo gallery, file share, calendaring app, and much more. Because Nextcloud includes a CalDAV component, you can create, export, import, and subscribe to iCalendar events and feeds. Nextcloud’s calendar offers all the usual options you’d expect from a digital calendar: color-coding, private and public events, importing and exporting .ics files, repeating events, location tags, descriptions, and so on.
You don’t have to use Google Calendar to receive and accept invitations from friends and colleagues, or to share your own calendars with others. And better yet, you don’t even have to use Nextcloud on all of your devices. You could use Nextcloud on your desktop, the built-in calendar on your phone, and something else entirely on your laptop. Thanks to open specifications, they’re all compatible.
You can install Nextcloud on your own server or hosting account, or you can join an existing Nextcloud provider’s server, or pay for a private instance of your own.
Thunderbird (Desktop)
The creators of Firefox also maintain the Thunderbird email client, a desktop application for Linux, Windows, and Mac for reading email outside of your web browser. Like Firefox, you can customize Thunderbird with plugins, and one of the most popular plugins is Lightning, a calendaring component. Lightning lets you create events and even publish them to a CalDAV service if you’re using one (like Nextcloud). It also supports color coding your different calendar feeds, has a variety of views, and even has a side panel for quick reference when you’re browsing your email.
The strength of Thunderbird, aside from its plugin architecture, is that it’s cross-platform. If you use different operating systems throughout the day, you can grant yourself a little bit of UI stability by using Thunderbird across all of them. You can’t make Windows or macOS change how they operate, but at least you can ensure that no matter what computer you’re on, your email and calendar, at least, will be exactly the same.
Evolution and Kontact (Desktop)
If you’ve used a desktop email client on any modern Linux distribution, then you’ve probably encountered GNOME’s Evolution. In addition to deftly handling enormous amounts of email, Evolution also has a calendar component. The calendar is iCalendar-coant, so you can import and export iCalendar events, and you can also subscribe to CalDAV feeds. Because it’s using the iCalendar specification, it features familiar options, such as repeating events, description, location, and so on.
The Evolution calendar offers several ways to view your scheduled events. The usual week and month views are available, but you can also view the «work week» (omitting the weekends, which admittedly only applies to a subset of workers), the day, and just a task list with no empty space. It also provides a task list for the current day in its email pane, so you don’t have to click over to your calendar just to see what’s coming up later on.
For KDE users, Kontact contains the Korganizer, a similar calendar component similar to the one in Evolution.
Etar (Mobile)
The stock Android calendar itself is actually open source, so you may already be using an open source client for your calendar on your mobile. However, not all devices ship with that calendar, so you can download a similar one from the F-Droid repository or check out the source on GitHub. It uses the same visual style as Android itself, so it looks and feels completely integrated with the rest of your mobile OS. It has views for the month, week, day, and just your daily agenda. It’s iCalendar-compliant, so you can share calendars, import and export .ics files, and subscribe to CalDAV feeds.
AgenDAV (Web)
In the modern world, many of us depend on being able to access our calendar from anywhere, regardless of what device we happen to have in hand, and there’s little substitute for a solid web calendar. While there are many web tools that can pull in data from CalDAV, my favorite is AgenDAV, which has a similar look and feel to Google Calendar. Unlike Nextcloud, there aren’t any AgenDAV hosts out there that you can join. If you want to run an AgenDAV server, you have to host and install it yourself. Also unlike Nextcloud, however, AgenDAV is just a calendar, so you don’t have the added complexity or bloat of a bunch of web apps you may have no intention of using.
AgenDAV talks CalDAV, and it does so fluently. It has all the CalDAV features you need to interface with other CalDAV calendars, and the other features (like color coding) that most of us have come to expect from a calendar web app.
These are far from the only tools you might consider for keeping a calendar using open source. There are plenty of others offering their own selection of features. Which open source tools do you use for keeping a calendar? Have you hacked together a solution using org-mode and Git? Or have you done something more inventive? Let us know in the comment below!
Note from the Editor: This article was originally published in 2016 and has been updated with new information.
This work is licensed under a Creative Commons Attribution-Share Alike 4.0 International License.
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calendar
Qt Huge Project
A simple well-designed desktop calendar for Windows, Linux and OS X.
Features
- Remind you what to do.
- Save your daily files using Drag and Drop technology.
- Export and import your to-do lists to help you share your idea with others.
- Search your to-do lists and files.
- Use SQLite database with journal to protect your data.
- Open Source, so you can do whatever you want.
Building
- Run
lrelease calendar.pro - Run
qmake - Run
make
or
Just open calendar.pro with Qt Creator.
calendar
scheduling
events
tasks
weather
open-source
customizable
online-calendar-integration
Open source desktop calendar application for Windows, Mac and Linux, supporting events, tasks and weather info, lightweight and customizable with online calendar integration.
What is Rainlendar?
Rainlendar is an open source desktop calendar and task management application developed by Rainlendar Ltd. It is available for Windows, macOS, and Linux operating systems.
Some key features of Rainlendar include:
- Lightweight application with low memory usage
- Customizable skins and layouts
- Supports calendar events, tasks/todos, and weather information
- Online calendar integration with Google Calendar, Outlook, iCloud, and other services
- Available in over 50 languages
- Open source software released under GNU GPL v2 license
Rainlendar allows users to manage events and tasks in a user-friendly desktop interface. Its customizable skins and compact footprint make it a popular choice over bulky calendar suites. Users praise Rainlendar for being highly customizable yet lightweight.
Compared to default Windows and Mac calendars, Rainlendar provides advanced configuration options and better support for online calendar services. The Pro version unlocks additional premium skins and features like exporting data to Excel.
Overall, Rainlendar is a versatile desktop calendar and task utility known for its low resource usage, abundant customization options, and support for online calendar services across platforms.
Rainlendar Features
Features
- Desktop calendar
- Event management
- Task management
- Weather information
- Customizable interface
- Lightweight
- Online calendar integration
Pros
Open source
Free
Lightweight
Customizable
Cross-platform
Online calendar integration
Weather integration
Cons
Limited features compared to proprietary options
No mobile app
Official Links
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Fantastical is a popular calendar application developed by Flexibits for Mac, iOS, iPadOS, and watchOS devices. It provides an intuitive user interface that allows users to quickly create, view, and manage events and reminders across their calendar.One of the standout features of Fantastical is its advanced natural language event parser….
Tuta
Tuta is an open source, privacy-focused email service launched in 2014. It emphasizes security and anonymity for its users. Some key features of Tuta include:End-to-end encryption — Emails are encrypted between the user and recipient, preventing third parties from accessing content.Anonymous sign up — No phone number or other personal…
Notion Calendar
Notion Calendar is a feature-rich calendar and task management application designed for personal use as well as for teams and organizations. It seamlessly combines calendar, task list, Kanban board, and reminder functionalities into one unified platform.Some of the key features of Notion Calendar include:Interactive and customizable calendar views like day,…
DigiCal
DigiCal is a free, open source calendar and scheduling application designed for the Windows platform. It provides a variety of tools for organizing appointments, events, reminders, and tasks into a simple yet functional interface.With DigiCal, users can easily create and view calendars by day, week, month, or schedule. Events, reminders,…
Cozi
Cozi is a free web and mobile application designed to help families stay organized and coordinated. It serves as a shared family calendar, shopping list manager, to-do list organizer, recipe box, and more.Key features of Cozi include:Shared family calendar — All family members can view, edit, and add events to…
Morgen
Morgen is a cloud-based project management and collaboration tool designed for agile teams. It aims to provide an all-in-one solution to plan, organize, track, and manage work across organizations.Key features of Morgen include:Kanban boards to visualize work and track progressCustomizable workflows and automation to streamline processesRoadmaps and release planning toolsTime…
Calendar Lock PEA
Calendar Lock PEA is software designed to lock down and protect calendars and schedules from unwanted changes. It works by integrating with popular calendar platforms like Outlook, Google Calendar, Office 365, and more to provide edit protection and prevent events, appointments, and meetings from being modified, moved, or deleted without…
Greg
Greg is an open-source, cross-platform personal information manager and note taking application. It is designed to help you easily capture ideas, organize notes, manage tasks, track appointments, and more.Some of the key features of Greg include:Intuitive and clean interface for quickly capturing notes, ideas, to-do’s, and moreSupport for formatting options…
Fossify Calendar
Fossify Calendar is a free, open-source calendar and scheduling application. It is designed to be a full-featured alternative to proprietary options like Microsoft Outlook Calendar and Google Calendar.With Fossify Calendar, users can view their schedule in a variety of calendar formats including day, week, month, and schedule. It provides the…
Calendar Buddy
Calendar Buddy is an intuitive and versatile calendar and scheduling software designed to help professionals, teams, and businesses organize events, manage time, and boost productivity.Key features include:Dynamic calendar views (day, week, month) with drag-and-drop functionality for easy event schedulingAbility to set up multiple color-coded calendars (work, personal, team) in one…
Proton Calendar
Proton Calendar is a free and open source calendar application developed by Proton Technologies AG, the company behind privacy-focused services like ProtonMail and ProtonVPN. It launched in 2022 as part of Proton’s vision to create an integrated ecosystem of online services with a strong emphasis on security and privacy protections.Like…
DeskTask
DeskTask is a lightweight yet feature-rich project management software designed specifically for small teams and businesses. Offering a free plan for up to 5 users, it aims to provide an affordable and easy-to-use alternative to complex PM tools better suited for large enterprises.The software focuses on task management within projects….
Wtplan
wtplan is an open-source, web-based project management and collaboration software. Developed using PHP and MySQL, it allows teams to plan projects, assign tasks, track progress, and work together more effectively.Some of the key features of wtplan include:Interactive Gantt charts for visualizing project timelines and schedulesKanban boards for managing tasks and…
HEY Calendar
HEY is an email service launched in 2020 by Basecamp, the project management and collaboration software company. It aims to provide a better, less chaotic email experience by cutting down on distractions and unnecessary emails.Some key features of HEY include:The Imbox — this contains only emails HEY deems important, reducing…
YouCanBook.Me
YouCanBook.Me is an intuitive online booking and scheduling software designed for small businesses who offer appointment-based services. With YouCanBook.Me, service providers can easily manage appointments, classes, and events directly on their website.Key features include:Online booking widget allows customers to self-schedule appointments on your websiteCalendar syncing connects your booking calendar across…
CalenGoo
CalenGoo is a user-friendly online calendar and scheduling application launched in 2012. As a web-based software, CalenGoo can be accessed from any device through a browser making it convenient for users to manage their events, appointments, and schedules from anywhere.Key features of CalenGoo include:Event creation with ability to set notifications…
Desktop Calendar
Desktop Calendar is a free, open-source calendar and scheduling application available for Windows, Mac, and Linux operating systems. With an easy-to-use interface, it helps you to efficiently organize and track events, tasks, and contacts.Key features include:Intuitive calendar views — Day, Week, Month, Year. Easily browse past and future dates.Create events…
GroupCal
GroupCal is a free online calendar and scheduling application designed for teams and groups. It allows creating multiple shared calendars that team members can view, edit, and manage events and tasks on. Some key features of GroupCal include:Calendar Sharing — Share calendars with your team and control permissions on viewing,…
Do-Organizer
do-Organizer is a free, open source digital notebook and organization app available for Windows, Mac, Linux, iOS and Android. It allows users to take notes, create to-do lists, save images and links, and organize everything in one unified workspace.Some key features of do-Organizer include:Clean and intuitive interface for creating notes,…
Desktop iCalendar
Desktop iCalendar is a full-featured calendar and task management application for desktop computers. Unlike simple calendar apps, Desktop iCalendar provides robust options for organizing your schedule.With Desktop iCalendar you can:Create calendar events with details like location, attendees, alerts etc.View your calendar by day, week, month, or schedule viewSet up recurring…
Simple Calendar
Simple Calendar is a popular open source calendar application for Android devices. Developed by Simple Mobile Tools, it is designed to provide a lightweight and easy-to-use calendar without unnecessary bloat or complicated features.Some key features of Simple Calendar include:Clean and intuitive interface for viewing, adding, and managing calendar eventsSupport for…
Nextcloud Calendar
Nextcloud Calendar is an open-source calendar and scheduling application that seamlessly integrates with the Nextcloud file hosting and collaboration platform. It provides users with a variety of tools to view, edit, and manage calendars, events, tasks, and scheduling right from Nextcloud.Some key features of Nextcloud Calendar include:Web-based interface for easy…
Reminder Commander
Reminder Commander is a versatile reminder and task management application for Windows. With an easy-to-use interface, Reminder Commander makes it simple to stay organized and on top of your to-do list.You can quickly create reminders and to-do items, set due dates and times, repeat reminders, categorize tasks, and set priority…
UKs Kalender
UKs Kalender is a free and open-source calendar application for Android devices. Developed by a European team of developers, it focuses on providing a fast, intuitive and customizable calendar experience.Some of the key features of UKs Kalender include:Clean and simple interface — Easy to navigate views for day, week, month…
RemindMe desktop calendar
RemindMe is a free and open-source calendar and task management app for Windows, Mac, and Linux operating systems. It provides users with an easy way to schedule appointments, set reminders, create to-do lists, and organize their schedules.Some key features of RemindMe include:Intuitive interface for adding events, reminders, notes, and tasksSupports…
GNOME Calendar
GNOME Calendar is a feature-rich, easy-to-use calendar application developed by the GNOME project for Linux and Unix-like operating systems. As part of the GNOME desktop environment, it tightly integrates with other GNOME applications and is focused on usability and simplicity.With GNOME Calendar, users can view and manage events from multiple…
Active Desktop Calendar
Active Desktop Calendar is a free desktop calendar software application designed for Windows. It displays your calendar events, tasks, and holidays directly on your desktop background or wallpaper for quick and convenient access.Some key features of Active Desktop Calendar include:Syncs with Google Calendar, Outlook, Office 365, Exchange, iCloud, and other…
Zoho Calendar
Zoho Calendar is a feature-rich online calendar and scheduling service offered by Zoho Corporation. It is designed for individuals and teams to organize meetings, appointments, events, and to-do lists in one place. Some key features and benefits of Zoho Calendar include:Intuitive user interface for creating and managing events/meetingsAbility to set…
BORG Calendar
BORG is a free and open source calendar and task management application developed by Borlabs for Windows, Linux and Android. It features a clean and intuitive interface that allows easy organization of events, tasks, contacts and other data.Some key features of BORG include:Ability to synchronize calendar and tasks between devices…
Outlook on the Desktop
Outlook on the Desktop is a personal information manager application developed by Microsoft. It is included in Microsoft Office suite of productivity applications for Windows and macOS operating systems.As an email client, Outlook provides the tools to send, receive, and organize email messages. It supports multiple email accounts, allowing users…
30 Boxes
30 Boxes is a cloud-based document management and file sharing service. It provides a simple, user-friendly way for individuals and teams to store, organize, collaborate on, share, and access documents and files from anywhere.Key features of 30 Boxes include:Cloud storage — Store all your files and documents securely in the…
Attendexer
Attendexer is a cloud-based time tracking and productivity management software designed specifically for remote teams and distributed workforces. It provides a suite of features to help managers and employees track time, manage projects, monitor productivity, and optimize workflows.Key features of Attendexer include:Automatic time tracking based on activity levels on computers…
SSuite My Calendar Diary
SSuite My Calendar Diary is a free personal information management application for Windows. It combines a calendar, daily planner, diary, and note-taking features into one easy-to-use program to help users organize their schedules and document their lives.Key features include:Calendar with day, week, month, and year views for scheduling appointments and…
GMinder
GMinder is a free and open-source mind mapping and brainstorming software application. It provides users with an intuitive interface to create mind maps that organize ideas, concepts, notes, images, and tasks visually using branches, connections, and tree-like structures.Some key features of GMinder include:Free to download and use with no ads…
Gsimplecal
gsimplecal is an open source calendar and scheduling desktop application designed for the Linux operating system. It provides a user-friendly interface for viewing, creating, and managing events, appointments, reminders, and tasks.Some key features of gsimplecal include:Clean, intuitive GUI that integrates nicely with GNOME Shell and other desktop environmentsDay, week, month,…
QOrganizer
qOrganizer is an open-source personal information manager and to-do list application designed for the Linux operating system. It allows users to keep track of important personal information including contacts, appointments, tasks, and notes in one organized application.Some key features of qOrganizer include:Contact Management — Store names, addresses, phone numbers, email…
Google Calendar Checker
Google Calendar Checker is a browser extension available for Chrome, Firefox, and Edge. It integrates with your Google calendar to provide at-a-glance information about your upcoming events.Once installed, the extension adds an icon to your browser toolbar that shows the number of events you have scheduled for today and tomorrow….
GMX Calendar
GMX Calendar is a free, web-based calendar and scheduling service offered by United Internet, the German technology company that also runs the GMX Mail email service. It features tools to organize and manage events, appointments, tasks, and other time-based items.Some key features of GMX Calendar include:Month, week, day, schedule, and…
ChronoFlo Calendar
ChronoFlo Calendar is a feature-rich calendar and scheduling application designed for individuals and teams who need to manage events, appointments, and schedules. It provides an intuitive interface and variety of tools to help users stay organized.Some key features of ChronoFlo Calendar include:Multiple calendar views (day, week, month, year) with drag-and-drop…
MemoCalendar.net
MemoCalendar.net is a free online calendar and task management web application. It provides users with features to help organize schedules, events, tasks, and reminders.With MemoCalendar, users can create multiple customizable calendars to keep track of different aspects of their life — work, home, family, etc. Calendars and tasks can be…
SyncSlot
SyncSlot is an easy-to-use online booking and appointment scheduling software designed for solopreneurs, small teams, and growing businesses. It provides a customizable platform to manage appointments, client data, reminders, payments, and more in one place.Key features include:Online booking pages and forms for clients to self-scheduleCalendar syncing and availability settingsCustom booking…
HipCal
HipCal is a free online calendar and scheduling application designed for small businesses, teams, and groups. It provides an easy way for users to manage their time and coordinate schedules with others.Some key features of HipCal include:Multiple calendar views (day, week, month) to visualize schedulesAbility to create and color-code multiple…
KeepTime
KeepTime is a cloud-based time tracking and project management software designed for agencies, consultants, accountants, and other professional services firms. It provides an all-in-one solution to record billable hours, manage projects, track expenses, create invoices, and analyze productivity.Key features of KeepTime include:Time Tracking — Automatically track time or enter it…
ReminderFox
ReminderFox is a free calendar and task management extension for the Firefox web browser. It provides users with an easy way to set reminders, organize tasks, and manage events directly within Firefox.Some key features of ReminderFox include:Create reminders for upcoming tasks and eventsSet custom reminders with date/time or location-based triggersOrganize…
Calendarific
Calendarific is a SaaS API that provides access to comprehensive global holiday, observance, and event data. It offers information on over 20,000 holidays, observances, events, and seasons across over 200 countries as well as helpful metadata like descriptions, search keywords, and suggestions for gifts and activities.The Calendarific API enables developers…
Calendarscope
Calendarscope is a feature-rich online calendar and scheduling application designed for teams and busy professionals who need to effectively manage their time. It provides a variety of tools to help users organize their schedules, collaborate with others, and stay on top of important events and tasks.Some key features of Calendarscope…
PreMinder
PreMinder is an easy-to-use appointment scheduling and reminder software designed specifically for small businesses and solo entrepreneurs like hair salons, spas, photographers, consultants, and coaches. It allows users to manage appointments, client data, employee shifts, and automate appointment reminders via email, text message, or voice calls.Key features include:Appointment scheduler with…
OrgCalendar
OrgCalendar is an open-source calendar and scheduling application. It allows users to manage their events, appointments, and schedules in a highly flexible manner.Some key features of OrgCalendar include:Ability to create and edit calendar events with details like title, date/time, location, descriptions, attachments etc.Calendar, week, month, year and agenda views of…
Family Tasks
Family Tasks is a shared task and calendar management app designed specifically for busy families to stay organized. It allows parents to assign chores, to-dos and reminders to children, track their progress, and manage a centralized family calendar.Key features of Family Tasks include:Shared family task lists and calendar — Parents…
Handy Calendar
Handy Calendar is a free calendar and scheduling application designed for the Windows operating system. With an easy-to-use interface, Handy Calendar allows users to efficiently organize and manage daily events and tasks.Key features of Handy Calendar include:Multiple calendar views — Switch between day, week, month, year, and agenda layoutsEvent creation…
Visual Calendar for Tablets
Visual Calendar for Tablets is a feature-rich calendar and scheduling app built for tablet devices. It provides an interactive and visually appealing way to manage your calendar, events, appointments and reminders.With its simple yet powerful interface, Visual Calendar allows you to easily view, enter and edit calendar items. You can…