diff --git a/lib/Rrd/Temperature.php b/lib/Rrd/Temperature.php
index 290c659..4b66d0f 100644
--- a/lib/Rrd/Temperature.php
+++ b/lib/Rrd/Temperature.php
@@ -135,21 +135,22 @@ class Temperature
      * output graph.
      *
      * @param string $type  output graph type
+     * @param int    $num   output period of graph type
      * @param string $fpath output image file path
      *
      * @return bool false if failure
      */
-    public function outputGraph(string $type, string $fpath): bool
+    public function outputGraph(string $type, int $num, string $fpath): bool
     {
         static $colors = [
             '#FF0000', '#00FF00', '#0000FF', '#FFFF00', '#00FFFF', '#FF00FF',
             '#FF9999', '#99FF99', '#9999FF', '#FFFF99', '#99FFFF', '#FF99FF',
         ];
-        static $types = ['hour', 'day', 'week', 'month', 'year', '3year'];
+        static $types = ['hour', 'day', 'week', 'month', 'year'];
         if (!in_array($type, $types)) {
             return false;
         }
-        $start = '3year' == $type ? '-3year' : '-1'.$type;
+        $start = sprintf('-%u%s', $num, $type);
         $options = [
             '--imgformat', 'PNG',
             '--lower-limit', '10',
@@ -160,7 +161,7 @@ class Temperature
             '--height', '200',
             '--units-exponent', '0',
             '--vertical-label', "Temperature [\xc2\xb0C]",
-            '--title', 'Server Room Temperature - by '.$type,
+            '--title', 'Server Room Temperature - by '.$num.$type.'(s)',
         ];
         $idlen = 0;
         foreach ($this->sensorIds as $key => $id) {
diff --git a/sbin/update.php b/sbin/update.php
index 6791e14..4a4b373 100644
--- a/sbin/update.php
+++ b/sbin/update.php
@@ -16,7 +16,16 @@ for ($i = 0; $i < $num; ++$i) {
     $now = time();
     $rrdtemp->update($id, $now, $value);
 }
-foreach ($types = ['hour', 'day', 'week', 'month', 'year', '3year'] as $type) {
-    $fpath = APPDIR.'/'.$config['images_dir'].'/graph-'.$type.'.png';
-    $rrdtemp->outputGraph($type, $fpath);
+$types = [
+    'hour' => [1, 3, 6, 12],
+    'day' => [1, 3],
+    'week' => [1, 2],
+    'month' => [1, 3, 6],
+    'year' => [1, 3, 5, 10],
+];
+foreach ($types as $type => $nums) {
+    foreach ($nums as $num) {
+        $fpath = APPDIR.'/'.$config['images_dir'].'/graph-'.(1 === $num ? '' : $num).$type.'.png';
+        $rrdtemp->outputGraph($type, $num, $fpath);
+    }
 }