diff --git a/calendar/inc/class.calendar_import_ical.inc.php b/calendar/inc/class.calendar_import_ical.inc.php
index 610cf730c7..43ce8bd359 100644
--- a/calendar/inc/class.calendar_import_ical.inc.php
+++ b/calendar/inc/class.calendar_import_ical.inc.php
@@ -144,18 +144,21 @@ class calendar_import_ical implements importexport_iface_import_plugin  {
 		$owner = $plugin_options['cal_owner'];
 
 		// Purge
-		$remove_past = new Api\DateTime();
-		$remove_future = new Api\DateTime();
-		$plugin_options = array_merge(array('remove_past' => 100, 'remove_future' => 365), $plugin_options);
-		foreach(array('remove_past','remove_future') as $date)
+		if($plugin_options['empty_before_import'])
 		{
-			${$date}->add( (($date == 'remove_past' ? -1 : 1) * (int)$plugin_options[$date]) . ' days');
+			$remove_past = new Api\DateTime();
+			$remove_future = new Api\DateTime();
+			$plugin_options = array_merge(array('remove_past' => 100, 'remove_future' => 365), $plugin_options);
+			foreach(array('remove_past','remove_future') as $date)
+			{
+				${$date}->add( (($date == 'remove_past' ? -1 : 1) * (int)$plugin_options[$date]) . ' days');
+			}
+			$this->purge_calendar(
+					$owner,
+					array('from' => $remove_past, 'to' => $remove_future),
+					$plugin_options['no_notification']
+			);
 		}
-		$this->purge_calendar(
-				$owner,
-				array('from' => $remove_past, 'to' => $remove_future),
-				$plugin_options['no_notification']
-		);
 
 		// User wants conflicting events to not be imported
 		if($_definition->plugin_options['skip_conflicts'])
diff --git a/calendar/inc/class.calendar_wizard_import_ical.inc.php b/calendar/inc/class.calendar_wizard_import_ical.inc.php
index 2dfc3cdaff..3e2ad89c56 100644
--- a/calendar/inc/class.calendar_wizard_import_ical.inc.php
+++ b/calendar/inc/class.calendar_wizard_import_ical.inc.php
@@ -70,7 +70,7 @@ class calendar_wizard_import_ical
 		{
 			$content['text'] = $this->steps['wizard_step55'];
 			$content['step'] = 'wizard_step55';
-			foreach(array('skip_conflicts','remove_past','remove_future') as $field)
+			foreach(array('skip_conflicts','empty_before_import','remove_past','remove_future') as $field)
 			{
 				if(!$content[$field] && array_key_exists($field, $content['plugin_options']))
 				{
diff --git a/calendar/templates/default/import.ical_conditions.xet b/calendar/templates/default/import.ical_conditions.xet
index 79b27d9d61..8b9ca63a29 100644
--- a/calendar/templates/default/import.ical_conditions.xet
+++ b/calendar/templates/default/import.ical_conditions.xet
@@ -9,9 +9,13 @@
 				<description value="Do not import conflicting events"/>
 				<checkbox id="skip_conflicts"/>
 			</hbox>
-			<description id="delete_title" value="Empty target calendar before importing" font_style="b" class="et2_bold"/>
-			<integer label="How many days to be removed in the past (default 100)" id="remove_past"/>
-			<integer label="How many days to be removed in the future (default 365)" id="remove_future"/>
+			<description/>
+			<hbox>
+				<description id="delete_title" value="Empty target calendar before importing" font_style="b" class="et2_bold"/>
+				<checkbox id="empty_before_import" onchange="var enabled = widget.getValue() == 'true'; var past = widget.getRoot().getWidgetById('remove_past'); var future = widget.getRoot().getWidgetById('remove_future');past.set_disabled(!enabled);future.set_disabled(!enabled);return true;"/>
+			</hbox>
+			<integer label="How many days to be removed in the past (default 100)" id="remove_past" disabled="!@empty_before_import"/>
+			<integer label="How many days to be removed in the future (default 365)" id="remove_future" disabled="!@empty_before_import"/>
 		</vbox>
 		<styles>
 			#importexport-wizardbox_delete_title {