diff --git a/index.php b/index.php
index 9293e7b..86e168f 100644
--- a/index.php
+++ b/index.php
@@ -23,7 +23,8 @@ if(@filemtime($cachefile) + $cachetime < time()) {
 //$iCal->initURL($ical);
 
 # Load calendar entries
-$events = $iCal->sortEventsWithOrder($iCal->eventsFromInterval('1 month'));
+$interval = max(filter_input(INPUT_GET, 'interval', FILTER_VALIDATE_INT, array('options' => array('min_range' => 1, 'max_range' => 12))), 1);
+$events = $iCal->sortEventsWithOrder($iCal->eventsFromInterval($interval.' month'));
 
 $filter = filter_input(INPUT_GET, 'filter', FILTER_SANITIZE_SPECIAL_CHARS);