diff --git a/lib/classes/user.php b/lib/classes/user.php
index 49672295cdc..6925e0224f6 100644
--- a/lib/classes/user.php
+++ b/lib/classes/user.php
@@ -461,7 +461,7 @@ class core_user {
                 'choices' => array_merge(array('' => ''), get_string_manager()->get_list_of_countries(true, true)));
         $fields['lang'] = array('type' => PARAM_LANG, 'null' => NULL_NOT_ALLOWED, 'default' => $CFG->lang,
                 'choices' => array_merge(array('' => ''), get_string_manager()->get_list_of_translations(false)));
-        $fields['calendartype'] = array('type' => PARAM_NOTAGS, 'null' => NULL_NOT_ALLOWED, 'default' => $CFG->calendartype,
+        $fields['calendartype'] = array('type' => PARAM_PLUGIN, 'null' => NULL_NOT_ALLOWED, 'default' => $CFG->calendartype,
                 'choices' => array_merge(array('' => ''), \core_calendar\type_factory::get_list_of_calendar_types()));
         $fields['theme'] = array('type' => PARAM_THEME, 'null' => NULL_NOT_ALLOWED,
                 'default' => theme_config::DEFAULT_THEME, 'choices' => array_merge(array('' => ''), get_list_of_themes()));
diff --git a/webservice/externallib.php b/webservice/externallib.php
index 84b0fd4b40d..b091147691e 100644
--- a/webservice/externallib.php
+++ b/webservice/externallib.php
@@ -197,6 +197,14 @@ class core_webservice_external extends external_api {
         // User home page.
         $siteinfo['userhomepage'] = get_home_page();
 
+        // Calendar.
+        $siteinfo['sitecalendartype'] = $CFG->calendartype;
+        if (empty($USER->calendartype)) {
+            $siteinfo['usercalendartype'] = $CFG->calendartype;
+        } else {
+            $siteinfo['usercalendartype'] = $USER->calendartype;
+        }
+
         return $siteinfo;
     }
 
@@ -259,7 +267,9 @@ class core_webservice_external extends external_api {
                 'userhomepage' => new external_value(PARAM_INT,
                                                         'the default home page for the user: 0 for the site home, 1 for dashboard',
                                                         VALUE_OPTIONAL),
-                'siteid'  => new external_value(PARAM_INT, 'Site course ID', VALUE_OPTIONAL)
+                'siteid'  => new external_value(PARAM_INT, 'Site course ID', VALUE_OPTIONAL),
+                'sitecalendartype'  => new external_value(PARAM_PLUGIN, 'Calendar type set in the site.', VALUE_OPTIONAL),
+                'usercalendartype'  => new external_value(PARAM_PLUGIN, 'Calendar typed used by the user.', VALUE_OPTIONAL),
             )
         );
     }
diff --git a/webservice/tests/externallib_test.php b/webservice/tests/externallib_test.php
index f845b622b2b..b5bea8ddb23 100644
--- a/webservice/tests/externallib_test.php
+++ b/webservice/tests/externallib_test.php
@@ -122,6 +122,12 @@ class core_webservice_externallib_testcase extends externallib_advanced_testcase
         $this->assertEquals(true, $siteinfo['usercanmanageownfiles']);
 
         $this->assertEquals(HOMEPAGE_MY, $siteinfo['userhomepage']);
+        $this->assertEquals($CFG->calendartype, $siteinfo['sitecalendartype']);
+        if (!empty($USER->calendartype)) {
+            $this->assertEquals($USER->calendartype, $siteinfo['usercalendartype']);
+        } else {
+            $this->assertEquals($CFG->calendartype, $siteinfo['usercalendartype']);
+        }
 
         // Now as admin.
         $this->setAdminUser();
diff --git a/webservice/upgrade.txt b/webservice/upgrade.txt
index 895a5f90a57..2301a7c6e24 100644
--- a/webservice/upgrade.txt
+++ b/webservice/upgrade.txt
@@ -3,6 +3,11 @@ information provided here is intended especially for developers.
 
 This information is intended for authors of webservices, not people writing webservice clients.
 
+=== 3.4 ===
+
+* External function core_webservice_external::get_site_info() now returns the calendar type used in the site and
+  by the user in the sitecalendartype and usercalendartype fields.
+
 === 3.2 ===
 
 * webservice->get_external_functions now returns the external function list ordered by name ASC.