diff --git a/appinfo/info.xml b/appinfo/info.xml
index 49da0f238..c7fc3da44 100644
--- a/appinfo/info.xml
+++ b/appinfo/info.xml
@@ -62,6 +62,7 @@
         <command>OCA\Deck\Command\UserExport</command>
         <command>OCA\Deck\Command\BoardImport</command>
         <command>OCA\Deck\Command\TransferOwnership</command>
+        <command>OCA\Deck\Command\CalendarToggle</command>
     </commands>
     <activity>
         <settings>
diff --git a/composer.lock b/composer.lock
index e0c144760..14199b9c1 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "6950663d9d213151028e780637480220",
+    "content-hash": "2a3a67d1b7c70fe1cee2183c26b0c906",
     "packages": [
         {
             "name": "justinrainbow/json-schema",
diff --git a/lib/Command/CalendarToggle.php b/lib/Command/CalendarToggle.php
new file mode 100644
index 000000000..2381cff94
--- /dev/null
+++ b/lib/Command/CalendarToggle.php
@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\Deck\Command;
+
+use OCP\IConfig;
+use OCP\IUserManager;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class CalendarToggle extends Command {
+	private IUserManager $userManager;
+	private IConfig $config;
+
+	public function __construct(IUserManager $userManager, IConfig $config) {
+		parent::__construct();
+		$this->userManager = $userManager;
+		$this->config = $config;
+	}
+
+	protected function configure() {
+		$this
+			->setName('deck:calendar-toggle')
+			->setDescription('Enable or disable Deck calendar/tasks integration for all existing users. Users can still change their own setting afterwards. Only affects users that already exist at the time of execution.')
+			->addOption(
+				'on',
+				null,
+				InputOption::VALUE_NONE,
+				'Enable calendar/tasks integration for all existing users (users can opt-out later)'
+			)
+			->addOption(
+				'off',
+				null,
+				InputOption::VALUE_NONE,
+				'Disable calendar/tasks integration for all existing users (users can opt-in later)'
+			);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$enable = $input->getOption('on');
+		$disable = $input->getOption('off');
+		if ($enable && $disable) {
+			$output->writeln('<error>Cannot use --on and --off together.</error>');
+			return 1;
+		}
+		if (!$enable && !$disable) {
+			$output->writeln('<error>Please specify either --on or --off.</error>');
+			return 1;
+		}
+		$value = $enable ? 'yes' : '';
+		$users = $this->userManager->search('');
+		$count = 0;
+		foreach ($users as $user) {
+			$uid = $user->getUID();
+			$this->config->setUserValue($uid, 'deck', 'calendar', $value);
+			$output->writeln("Set calendar integration to '" . ($enable ? 'on' : 'off') . "' for user: $uid");
+			$count++;
+		}
+		$output->writeln("Done. Updated $count existing users.");
+		return 0;
+	}
+}