diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 72bd2d34..a3fc6fb1 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -3353,7 +3353,7 @@ class calendar extends rcube_plugin
     $this->ui->init();
     $this->ui->addJS();
     $this->ui->init_templates();
-    $this->ui->calendar_list(); // set env['calendars']
+    $this->ui->calendar_list(array(), true); // set env['calendars']
 
     $uid   = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_GET);
     $mbox  = rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_GET);
diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index f41754ed..23b56cdc 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -207,11 +207,11 @@ class calendar_ui
   /**
    *
    */
-  function calendar_list($attrib = array())
+  function calendar_list($attrib = array(), $js_only = false)
   {
-    $html = '';
-    $jsenv = array();
-    $tree = true;
+    $html      = '';
+    $jsenv     = array();
+    $tree      = true;
     $calendars = $this->cal->driver->list_calendars(0, $tree);
 
     // walk folder tree
@@ -240,9 +240,14 @@ class calendar_ui
       );
     }
 
-    $this->rc->output->set_env('source', rcube_utils::get_input_value('source', rcube_utils::INPUT_GET));
     $this->rc->output->set_env('calendars', $jsenv);
-    $this->rc->output->add_gui_object('calendarslist', $attrib['id']);
+
+    if ($js_only) {
+      return;
+    }
+
+    $this->rc->output->set_env('source', rcube_utils::get_input_value('source', rcube_utils::INPUT_GET));
+    $this->rc->output->add_gui_object('calendarslist', $attrib['id'] ?: 'unknown');
 
     return html::tag('ul', $attrib, $html, html::$common_attrib);
   }
diff --git a/plugins/libkolab/skins/elastic/include/calendar.less b/plugins/libkolab/skins/elastic/include/calendar.less
index aa85a6fd..b4c07869 100644
--- a/plugins/libkolab/skins/elastic/include/calendar.less
+++ b/plugins/libkolab/skins/elastic/include/calendar.less
@@ -1343,6 +1343,11 @@ body.task-calendar {
         }
     }
 
+    .slot-nav {
+        display: flex;
+        align-items: center;
+    }
+
     .schedule-find-buttons {
         margin-right: 1rem;
         float: left;
@@ -1365,11 +1370,15 @@ body.task-calendar {
     }
 
     .schedule-options {
-        line-height: 2.8;
-
         label {
             vertical-align: middle;
         }
+
+        input.icon-checkbox + label:before {
+            margin-right:.25rem;
+            display: inline;
+            float: none;
+        }
     }
 
     .attendees-list {
@@ -1442,6 +1451,7 @@ body.task-calendar {
             td {
                 height: 1.8rem;
                 border-top: 1px solid @color-list-border;
+                white-space: nowrap;
             }
         }