diff --git a/pkgs/servers/web-apps/discourse/plugins/all-plugins.nix b/pkgs/servers/web-apps/discourse/plugins/all-plugins.nix
index 37f0a6b8681..27c749dea2e 100644
--- a/pkgs/servers/web-apps/discourse/plugins/all-plugins.nix
+++ b/pkgs/servers/web-apps/discourse/plugins/all-plugins.nix
@@ -3,6 +3,7 @@ let
   callPackage = newScope args;
 in
 {
+  discourse-calendar = callPackage ./discourse-calendar {};
   discourse-canned-replies = callPackage ./discourse-canned-replies {};
   discourse-checklist = callPackage ./discourse-checklist {};
   discourse-data-explorer = callPackage ./discourse-data-explorer {};
diff --git a/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/Gemfile b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/Gemfile
new file mode 100644
index 00000000000..8c192fc0385
--- /dev/null
+++ b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/Gemfile
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+gem 'rrule', '0.4.2', require: false
diff --git a/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/Gemfile.lock b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/Gemfile.lock
new file mode 100644
index 00000000000..b3c21c857d4
--- /dev/null
+++ b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/Gemfile.lock
@@ -0,0 +1,27 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activesupport (6.1.4)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      tzinfo (~> 2.0)
+      zeitwerk (~> 2.3)
+    concurrent-ruby (1.1.9)
+    i18n (1.8.10)
+      concurrent-ruby (~> 1.0)
+    minitest (5.14.4)
+    rrule (0.4.2)
+      activesupport (>= 4.1)
+    tzinfo (2.0.4)
+      concurrent-ruby (~> 1.0)
+    zeitwerk (2.4.2)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  rrule (= 0.4.2)
+
+BUNDLED WITH
+   2.2.20
diff --git a/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/default.nix b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/default.nix
new file mode 100644
index 00000000000..f4f179c07c0
--- /dev/null
+++ b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/default.nix
@@ -0,0 +1,18 @@
+{ lib, mkDiscoursePlugin, fetchFromGitHub }:
+
+mkDiscoursePlugin {
+  name = "discourse-calendar";
+  bundlerEnvArgs.gemdir = ./.;
+  src = fetchFromGitHub {
+    owner = "discourse";
+    repo = "discourse-calendar";
+    rev = "567712d8c02640574fbab081eb54b2f26349c88d";
+    sha256 = "sha256-r6rfbi/ScbM+SiAjeijXmr5R9wpJxzxGl52X5oV++5w=";
+  };
+  meta = with lib; {
+    homepage = "https://github.com/discourse/discourse-calendar";
+    maintainers = with maintainers; [ ryantm ];
+    license = licenses.mit;
+    description = "Adds the ability to create a dynamic calendar in the first post of a topic";
+  };
+}
diff --git a/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/gemset.nix b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/gemset.nix
new file mode 100644
index 00000000000..26db0e6fd10
--- /dev/null
+++ b/pkgs/servers/web-apps/discourse/plugins/discourse-calendar/gemset.nix
@@ -0,0 +1,76 @@
+{
+  activesupport = {
+    dependencies = ["concurrent-ruby" "i18n" "minitest" "tzinfo" "zeitwerk"];
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0kqgywy4cj3h5142dh7pl0xx5nybp25jn0ykk0znziivzks68xdk";
+      type = "gem";
+    };
+    version = "6.1.4";
+  };
+  concurrent-ruby = {
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0nwad3211p7yv9sda31jmbyw6sdafzmdi2i2niaz6f0wk5nq9h0f";
+      type = "gem";
+    };
+    version = "1.1.9";
+  };
+  i18n = {
+    dependencies = ["concurrent-ruby"];
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0g2fnag935zn2ggm5cn6k4s4xvv53v2givj1j90szmvavlpya96a";
+      type = "gem";
+    };
+    version = "1.8.10";
+  };
+  minitest = {
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "19z7wkhg59y8abginfrm2wzplz7py3va8fyngiigngqvsws6cwgl";
+      type = "gem";
+    };
+    version = "5.14.4";
+  };
+  rrule = {
+    dependencies = ["activesupport"];
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0w338b7dgvd144fl5b8xy2lfc6zgbcjac7b4z158jc8h070yzc9v";
+      type = "gem";
+    };
+    version = "0.4.2";
+  };
+  tzinfo = {
+    dependencies = ["concurrent-ruby"];
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "10qp5x7f9hvlc0psv9gsfbxg4a7s0485wsbq1kljkxq94in91l4z";
+      type = "gem";
+    };
+    version = "2.0.4";
+  };
+  zeitwerk = {
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1746czsjarixq0x05f7p3hpzi38ldg6wxnxxw74kbjzh1sdjgmpl";
+      type = "gem";
+    };
+    version = "2.4.2";
+  };
+}