{
 "schemaVersion": 1,
 "generated": "2026-10-30",
 "dataLicense": "CC BY-SA 4.0",
 "license": "CC BY-SA 4.0",
 "notice": "Data from Open Source Everything (https://opensourceeverything.org), licensed CC BY-SA 4.0: use it freely, credit the site, link to the page, and share changes under the same license. Listings were drafted with AI assistance and are managed by the r/TrueOpenSource moderators; check a project's own page before relying on a fact.",
 "id": "calendars",
 "name": "Calendar",
 "page": "https://opensourceeverything.org/g/calendars/",
 "category": "office",
 "categoryName": "Office & productivity",
 "job": "Keeping your events and reminders in one place and synced across your devices",
 "closedApps": [
  "Google Calendar",
  "Outlook Calendar"
 ],
 "coverage": "one-full",
 "alternatives": [
  {
   "id": "nextcloud-calendar",
   "name": "Nextcloud Calendar",
   "page": "https://opensourceeverything.org/p/nextcloud-calendar/",
   "summary": "A calendar app that runs on a Nextcloud server, letting you sync events from your devices and edit them in a web browser. It is for people and teams who want to keep their calendar on their own Nextcloud server.",
   "kind": "self_hosted",
   "setup": "advanced",
   "setupWhy": "You run it on your own server (a computer you set up and keep running), or from the command line.",
   "platforms": [
    "web",
    "server"
   ],
   "license": "AGPL-3.0",
   "licenseClass": "open",
   "licenseNeedsCheck": false,
   "stars": 1193,
   "forks": 338,
   "status": "active",
   "verified": false,
   "latestRelease": {
    "name": "v3.3.2",
    "date": "2022-06-02T07:23:46Z"
   },
   "code": "https://github.com/nextcloud/calendar",
   "website": "https://apps.nextcloud.com/apps/calendar",
   "download": null,
   "release": "https://github.com/nextcloud/calendar/releases/tag/v3.3.2",
   "family": null,
   "familyChildren": [],
   "howToHelp": {
    "contributingGuide": null,
    "goodFirstIssues": {
     "count": 5,
     "url": "https://github.com/nextcloud/calendar/issues?q=is%3Aopen%20is%3Aissue%20label%3A%22good%20first%20issue%22"
    },
    "helpWanted": {
     "count": 2,
     "url": "https://github.com/nextcloud/calendar/issues?q=is%3Aopen%20is%3Aissue%20label%3A%22help%20wanted%22"
    },
    "plugins": null
   },
   "project": "nextcloud-calendar",
   "rank": 1,
   "fit": "full",
   "note": "Needs a Nextcloud server",
   "why": "Does the whole job · Advanced setup",
   "score": 61.2
  },
  {
   "id": "thunderbird",
   "name": "Thunderbird",
   "page": "https://opensourceeverything.org/p/thunderbird/",
   "summary": "Thunderbird is a free, open-source email app for Windows, macOS and Linux that also includes calendars and contacts, with an Android app for email. It suits people who want to manage their email and calendars in one desktop program without relying on a big tech company.",
   "kind": "app",
   "setup": "easy",
   "setupWhy": "Install it like a normal app, or use it in your browser.",
   "platforms": [
    "windows",
    "mac",
    "linux",
    "android"
   ],
   "license": "MPL-2.0",
   "licenseClass": "open",
   "licenseNeedsCheck": false,
   "stars": null,
   "forks": null,
   "status": "active",
   "verified": true,
   "latestRelease": null,
   "code": null,
   "website": "https://www.thunderbird.net",
   "download": "https://www.thunderbird.net/download/",
   "release": null,
   "family": null,
   "familyChildren": [],
   "howToHelp": {
    "contributingGuide": null,
    "goodFirstIssues": null,
    "helpWanted": null,
    "plugins": {
     "label": "Build an add-on",
     "url": "https://developer.thunderbird.net/add-ons/about-add-ons"
    }
   },
   "project": "thunderbird",
   "rank": 2,
   "fit": "partial",
   "note": "Desktop only; no phone calendar app",
   "why": "Does part of the job · Verified · Easy setup",
   "score": 41.4
  },
  {
   "id": "fossify-calendar",
   "name": "Fossify Calendar",
   "page": "https://opensourceeverything.org/p/fossify-calendar/",
   "summary": "Fossify Calendar is a calendar app for Android phones that lets you plan events, reminders and repeating appointments. It is aimed at people who want a private calendar with no ads or tracking.",
   "kind": "app",
   "setup": "easy",
   "setupWhy": "Install it like a normal app, or use it in your browser.",
   "platforms": [
    "android"
   ],
   "license": "GPL-3.0",
   "licenseClass": "open",
   "licenseNeedsCheck": false,
   "stars": 2253,
   "forks": 243,
   "status": "active",
   "verified": false,
   "latestRelease": {
    "name": "1.12.1",
    "date": "2026-10-24T13:54:02Z"
   },
   "code": "https://github.com/FossifyOrg/Calendar",
   "website": "https://www.fossify.org",
   "download": null,
   "release": "https://github.com/FossifyOrg/Calendar/releases/tag/1.12.1",
   "family": {
    "relation": "continues",
    "of": null,
    "ofName": "Simple Calendar",
    "ofUrl": "https://github.com/SimpleMobileTools/Simple-Calendar",
    "since": null,
    "text": "Carries on Simple Calendar after it stopped",
    "why": "Fossify emerged as a fork of the discontinued Simple Mobile Tools apps, to continue them.",
    "sourceUrl": "https://github.com/FossifyOrg/.github/blob/main/profile/README.md"
   },
   "familyChildren": [],
   "howToHelp": {
    "contributingGuide": "https://github.com/FossifyOrg/Calendar/blob/HEAD/CONTRIBUTING.md",
    "goodFirstIssues": null,
    "helpWanted": null,
    "plugins": null
   },
   "project": "fossify-calendar",
   "rank": 3,
   "fit": "partial",
   "note": "Android only",
   "why": "Does part of the job · Easy setup",
   "score": 39.1
  },
  {
   "id": "etar-calendar",
   "name": "Etar Calendar",
   "page": "https://opensourceeverything.org/p/etar-calendar/",
   "summary": "Etar is a calendar app for Android phones that shows month, week, day and agenda views. It is for people who want a simple calendar that can keep events on the phone or sync them with a calendar server.",
   "kind": "app",
   "setup": "easy",
   "setupWhy": "Install it like a normal app, or use it in your browser.",
   "platforms": [
    "android"
   ],
   "license": "GPL-3.0",
   "licenseClass": "open",
   "licenseNeedsCheck": false,
   "stars": 2628,
   "forks": 450,
   "status": "active",
   "verified": false,
   "latestRelease": {
    "name": "v1.0.57",
    "date": "2026-07-27T15:31:40Z"
   },
   "code": "https://github.com/Etar-Group/Etar-Calendar",
   "website": "https://f-droid.org/packages/ws.xsoh.etar/",
   "download": null,
   "release": "https://github.com/Etar-Group/Etar-Calendar/releases/tag/v1.0.57",
   "family": null,
   "familyChildren": [],
   "howToHelp": {
    "contributingGuide": null,
    "goodFirstIssues": null,
    "helpWanted": {
     "count": 3,
     "url": "https://github.com/Etar-Group/Etar-Calendar/issues?q=is%3Aopen%20is%3Aissue%20label%3A%22help%20wanted%22"
    },
    "plugins": null
   },
   "project": "etar-calendar",
   "rank": 4,
   "fit": "partial",
   "note": "Android only",
   "why": "Does part of the job · Easy setup",
   "score": 37.3
  }
 ],
 "source": "https://opensourceeverything.org/g/calendars/",
 "group": "Calendar",
 "replaces": [
  "Google Calendar",
  "Outlook Calendar"
 ]
}