diff --git a/Gruntfile.js b/Gruntfile.js
index 69967fe1..51e5750d 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -13,7 +13,7 @@ module.exports = function (grunt) {
     "node_modules/bootstrap-markdown/locale/bootstrap-markdown.de.js",
     "node_modules/fullcalendar/index.global.js",
     "node_modules/luxon/build/global/luxon.js",
-    "node_modules/@fullcalendar/luxon2/index.global.js",
+    "node_modules/@fullcalendar/luxon3/index.global.js",
     "node_modules/jquery-validation/dist/jquery.validate.js",
     "node_modules/jquery-validation/dist/additional-methods.js",
     "softwerkskammer/frontend/3rd_party_js/bootstrap5-multidropdownhack.js",
diff --git a/package.json b/package.json
index 2228df2a..304379e3 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,8 @@
   },
   "dependencies": {
     "@fortawesome/fontawesome-free": "6.5.1",
-    "@fullcalendar/luxon2": "6.1.10",
+    "@fullcalendar/core": "6.1.10",
+    "@fullcalendar/luxon3": "6.1.10",
     "@popperjs/core": "2.11.8",
     "CoolBeans": "0.0.9",
     "awesome-bootstrap-checkbox": "1.0.1",
@@ -81,6 +82,7 @@
   },
   "devDependencies": {
     "ajv": "8.12.0",
+    "eslint": "8.56.0",
     "eslint-config-prettier": "9.1.0",
     "eslint-plugin-prettier": "5.1.2",
     "grunt": "1.6.1",
diff --git a/update.sh b/update.sh
index c997bf73..1ba2ea5b 100755
--- a/update.sh
+++ b/update.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 git pull
 corepack enable
-yarn install --frozen-lockfile
+yarn install --immutable
 git checkout -- yarn.lock
 yarn deploy
diff --git a/yarn.lock b/yarn.lock
index 43cac172..f9f7323d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -341,6 +341,30 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@eslint/eslintrc@npm:^2.1.4":
+  version: 2.1.4
+  resolution: "@eslint/eslintrc@npm:2.1.4"
+  dependencies:
+    ajv: "npm:^6.12.4"
+    debug: "npm:^4.3.2"
+    espree: "npm:^9.6.0"
+    globals: "npm:^13.19.0"
+    ignore: "npm:^5.2.0"
+    import-fresh: "npm:^3.2.1"
+    js-yaml: "npm:^4.1.0"
+    minimatch: "npm:^3.1.2"
+    strip-json-comments: "npm:^3.1.1"
+  checksum: 32f67052b81768ae876c84569ffd562491ec5a5091b0c1e1ca1e0f3c24fb42f804952fdd0a137873bc64303ba368a71ba079a6f691cee25beee9722d94cc8573
+  languageName: node
+  linkType: hard
+
+"@eslint/js@npm:8.56.0":
+  version: 8.56.0
+  resolution: "@eslint/js@npm:8.56.0"
+  checksum: 60b3a1cf240e2479cec9742424224465dc50e46d781da1b7f5ef240501b2d1202c225bd456207faac4b34a64f4765833345bc4ddffd00395e1db40fa8c426f5a
+  languageName: node
+  linkType: hard
+
 "@eslint/js@npm:^8.47.0":
   version: 8.47.0
   resolution: "@eslint/js@npm:8.47.0"
@@ -355,7 +379,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@fullcalendar/core@npm:~6.1.10":
+"@fullcalendar/core@npm:6.1.10, @fullcalendar/core@npm:~6.1.10":
   version: 6.1.10
   resolution: "@fullcalendar/core@npm:6.1.10"
   dependencies:
@@ -391,13 +415,13 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@fullcalendar/luxon2@npm:6.1.10":
+"@fullcalendar/luxon3@npm:6.1.10":
   version: 6.1.10
-  resolution: "@fullcalendar/luxon2@npm:6.1.10"
+  resolution: "@fullcalendar/luxon3@npm:6.1.10"
   peerDependencies:
     "@fullcalendar/core": ~6.1.10
-    luxon: ^2.0.0
-  checksum: 77b2fcc3bf222fbc27a611d35939c6869c71366a53b2de34dfbf40b1cc572712c862602aef3273aab59ed7c6480480d36d805f8f43bc67d05b25db6068f8e5ad
+    luxon: ^3.0.0
+  checksum: 8b0a436bd329d3b3cf169238c102ac71c82daf078e7996ac9f1a117d71438e712ba11a9944b47c699cd06023f182e03ad81a6ac516791a86fb8f72207f80f6ed
   languageName: node
   linkType: hard
 
@@ -434,6 +458,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@humanwhocodes/config-array@npm:^0.11.13":
+  version: 0.11.13
+  resolution: "@humanwhocodes/config-array@npm:0.11.13"
+  dependencies:
+    "@humanwhocodes/object-schema": "npm:^2.0.1"
+    debug: "npm:^4.1.1"
+    minimatch: "npm:^3.0.5"
+  checksum: d76ca802d853366094d0e98ff0d0994117fc8eff96649cd357b15e469e428228f597cd2e929d54ab089051684949955f16ee905bb19f7b2f0446fb377157be7a
+  languageName: node
+  linkType: hard
+
 "@humanwhocodes/module-importer@npm:^1.0.1":
   version: 1.0.1
   resolution: "@humanwhocodes/module-importer@npm:1.0.1"
@@ -448,6 +483,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@humanwhocodes/object-schema@npm:^2.0.1":
+  version: 2.0.1
+  resolution: "@humanwhocodes/object-schema@npm:2.0.1"
+  checksum: 9dba24e59fdb4041829d92b693aacb778add3b6f612aaa9c0774f3b650c11a378cc64f042a59da85c11dae33df456580a3c36837b953541aed6ff94294f97fac
+  languageName: node
+  linkType: hard
+
 "@istanbuljs/schema@npm:^0.1.2":
   version: 0.1.3
   resolution: "@istanbuljs/schema@npm:0.1.3"
@@ -746,6 +788,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ungap/structured-clone@npm:^1.2.0":
+  version: 1.2.0
+  resolution: "@ungap/structured-clone@npm:1.2.0"
+  checksum: 8209c937cb39119f44eb63cf90c0b73e7c754209a6411c707be08e50e29ee81356dca1a848a405c8bdeebfe2f5e4f831ad310ae1689eeef65e7445c090c6657d
+  languageName: node
+  linkType: hard
+
 "CoolBeans@npm:0.0.9":
   version: 0.0.9
   resolution: "CoolBeans@npm:0.0.9"
@@ -837,7 +886,8 @@ __metadata:
   resolution: "agora@workspace:."
   dependencies:
     "@fortawesome/fontawesome-free": "npm:6.5.1"
-    "@fullcalendar/luxon2": "npm:6.1.10"
+    "@fullcalendar/core": "npm:6.1.10"
+    "@fullcalendar/luxon3": "npm:6.1.10"
     "@popperjs/core": "npm:2.11.8"
     CoolBeans: "npm:0.0.9"
     ajv: "npm:8.12.0"
@@ -853,6 +903,7 @@ __metadata:
     csurf: "npm:1.11.0"
     datatables.net: "npm:1.13.8"
     datatables.net-bs5: "npm:1.13.8"
+    eslint: "npm:8.56.0"
     eslint-config-prettier: "npm:9.1.0"
     eslint-plugin-prettier: "npm:5.1.2"
     exifr: "npm:7.1.3"
@@ -2636,6 +2687,54 @@ __metadata:
   languageName: node
   linkType: hard
 
+"eslint@npm:8.56.0":
+  version: 8.56.0
+  resolution: "eslint@npm:8.56.0"
+  dependencies:
+    "@eslint-community/eslint-utils": "npm:^4.2.0"
+    "@eslint-community/regexpp": "npm:^4.6.1"
+    "@eslint/eslintrc": "npm:^2.1.4"
+    "@eslint/js": "npm:8.56.0"
+    "@humanwhocodes/config-array": "npm:^0.11.13"
+    "@humanwhocodes/module-importer": "npm:^1.0.1"
+    "@nodelib/fs.walk": "npm:^1.2.8"
+    "@ungap/structured-clone": "npm:^1.2.0"
+    ajv: "npm:^6.12.4"
+    chalk: "npm:^4.0.0"
+    cross-spawn: "npm:^7.0.2"
+    debug: "npm:^4.3.2"
+    doctrine: "npm:^3.0.0"
+    escape-string-regexp: "npm:^4.0.0"
+    eslint-scope: "npm:^7.2.2"
+    eslint-visitor-keys: "npm:^3.4.3"
+    espree: "npm:^9.6.1"
+    esquery: "npm:^1.4.2"
+    esutils: "npm:^2.0.2"
+    fast-deep-equal: "npm:^3.1.3"
+    file-entry-cache: "npm:^6.0.1"
+    find-up: "npm:^5.0.0"
+    glob-parent: "npm:^6.0.2"
+    globals: "npm:^13.19.0"
+    graphemer: "npm:^1.4.0"
+    ignore: "npm:^5.2.0"
+    imurmurhash: "npm:^0.1.4"
+    is-glob: "npm:^4.0.0"
+    is-path-inside: "npm:^3.0.3"
+    js-yaml: "npm:^4.1.0"
+    json-stable-stringify-without-jsonify: "npm:^1.0.1"
+    levn: "npm:^0.4.1"
+    lodash.merge: "npm:^4.6.2"
+    minimatch: "npm:^3.1.2"
+    natural-compare: "npm:^1.4.0"
+    optionator: "npm:^0.9.3"
+    strip-ansi: "npm:^6.0.1"
+    text-table: "npm:^0.2.0"
+  bin:
+    eslint: bin/eslint.js
+  checksum: 2be598f7da1339d045ad933ffd3d4742bee610515cd2b0d9a2b8b729395a01d4e913552fff555b559fccaefd89d7b37632825789d1b06470608737ae69ab43fb
+  languageName: node
+  linkType: hard
+
 "eslint@npm:^8.44.0":
   version: 8.47.0
   resolution: "eslint@npm:8.47.0"