diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 6285f6eb..a6e288dc 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -3096,9 +3096,10 @@ function rcube_calendar_ui(settings)
         $('#event-export-calendar').val(calendar.id);
 
       $('#event-export-range').change(function(e){
-        var custom = $('option:selected', this).val() == 'custom',
-          input = $('#event-export-startdate')
-        input.parent()[(custom?'show':'hide')]();
+        var custom = $(this).val() == 'custom', input = $('#event-export-startdate');
+
+        $(this)[custom ? 'removeClass' : 'addClass']('rounded-right'); // Elastic/Bootstrap
+        input[custom ? 'show' : 'hide']();
         if (custom)
           input.select();
       })
@@ -3109,8 +3110,8 @@ function rcube_calendar_ui(settings)
           'class': 'mainaction export',
           click: function() {
             if (form) {
-              var start = 0, range = $('#event-export-range option:selected', this).val(),
-                source = $('#event-export-calendar option:selected').val(),
+              var start = 0, range = $('#event-export-range', this).val(),
+                source = $('#event-export-calendar').val(),
                 attachmt = $('#event-export-attachments').get(0).checked;
 
               if (range == 'custom')
diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index 79b631d7..63ab9c3b 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -571,7 +571,7 @@ class calendar_ui
       html::label(array('for' => 'event-export-calendar', 'class' => 'col-sm-4 col-form-label'), $this->cal->gettext('calendar'))
         . html::div('col-sm-8', $this->calendar_select(array('name' => 'calendar', 'id' => 'event-export-calendar', 'class' => 'form-control custom-select'))));
 
-    $select = new html_select(array('name' => 'range', 'id' => 'event-export-range', 'class' => 'form-control custom-select'));
+    $select = new html_select(array('name' => 'range', 'id' => 'event-export-range', 'class' => 'form-control custom-select rounded-right'));
     $select->add(array(
         $this->cal->gettext('all'),
         $this->cal->gettext('onemonthback'),
@@ -583,11 +583,11 @@ class calendar_ui
       ),
       array(0,'1','2','3','6','12','custom'));
 
-    $startdate = new html_inputfield(array('name' => 'start', 'size' => 11, 'id' => 'event-export-startdate'));
+    $startdate = new html_inputfield(array('name' => 'start', 'size' => 11, 'id' => 'event-export-startdate', 'style' => 'display:none'));
 
     $html .= html::div('form-section form-group row',
       html::label(array('for' => 'event-export-range', 'class' => 'col-sm-4 col-form-label'), $this->cal->gettext('exportrange'))
-        . html::div('col-sm-8', $select->show(0) . html::span(array('style'=>'display:none'), $startdate->show())));
+        . html::div('col-sm-8 input-group', $select->show(0) . $startdate->show()));
 
     $checkbox = new html_checkbox(array('name' => 'attachments', 'id' => 'event-export-attachments', 'value' => 1, 'class' => 'form-check-input pretty-checkbox'));
     $html .= html::div('form-section form-check row',