Time detection: Add receiever to bootstrap method

refs #6078

library/Icinga/Application/Web.php

@@ -10,6 +10,7 @@ use Icinga\Authentication\Manager as AuthenticationManager;
 use Icinga\Exception\ConfigurationError;
 use Icinga\Exception\NotReadableError;
 use Icinga\Logger\Logger;
+use Icinga\Util\TimezoneDetect;
 use Icinga\Web\Request;
 use Icinga\Web\Response;
 use Icinga\Web\View;
@@ -273,10 +274,11 @@ class Web extends ApplicationBootstrap
      */
     protected function setupTimezone()
     {
+        $userTimezone = null;
+
         if ($this->user !== null && $this->user->getPreferences() !== null) {
-            $userTimezone = $this->user->getPreferences()->get('app.timezone');
-        } else {
-            $userTimezone = null;
+            $detect = new TimezoneDetect();
+            $userTimezone = $this->user->getPreferences()->get('app.timezone', $detect->getTimezoneName());
         }
 
         try {

library/Icinga/Util/TimezoneDetect.php

@@ -0,0 +1,108 @@
+<?php
+// {{{ICINGA_LICENSE_HEADER}}}
+// {{{ICINGA_LICENSE_HEADER}}}
+
+namespace Icinga\Util;
+
+use Icinga\Application\Platform;
+
+/**
+ * Retrieve timezone information from cookie
+ */
+class TimezoneDetect
+{
+    /**
+     * If detection was successful
+     *
+     * @var bool
+     */
+    private static $success;
+
+    /**
+     * Timezone offset in minutes
+     *
+     * @var int
+     */
+    private static $offset = 0;
+
+    /**
+     * @var string
+     */
+    private static $timezoneName;
+
+    /**
+     * Cookie name
+     *
+     * @var string
+     */
+    public static $cookieName = 'icingaweb2-tzo';
+
+    /**
+     * Timezone name
+     *
+     * @var string
+     */
+    private static $timezone;
+
+    /**
+     * Create new object and try to identify the timezone
+     */
+    public function __construct()
+    {
+        if (self::$success !== null) {
+            return;
+        }
+
+        if (Platform::isCli() === false && array_key_exists(self::$cookieName, $_COOKIE)) {
+            list($offset, $dst) = explode(',', $_COOKIE[self::$cookieName]);
+            $timezoneName = timezone_name_from_abbr('', (int)$offset, (int)$dst);
+
+            self::$success = (bool)$timezoneName;
+
+            if (self::$success === true) {
+                self::$offset = $offset;
+                self::$timezoneName = $timezoneName;
+            }
+        }
+    }
+
+    /**
+     * Get offset
+     *
+     * @return int
+     */
+    public function getOffset()
+    {
+        return self::$offset;
+    }
+
+    /**
+     * Get timezone name
+     *
+     * @return string
+     */
+    public function getTimezoneName()
+    {
+        return self::$timezoneName;
+    }
+
+    /**
+     * True on success
+     *
+     * @return bool
+     */
+    public function success()
+    {
+        return self::$success;
+    }
+
+    /**
+     * Reset object
+     */
+    public function reset()
+    {
+        self::$success = null;
+        self::$timezoneName = null;
+        self::$offset = 0;
+    }
+}

public/js/icinga/timezone.js

@@ -31,7 +31,7 @@
 
     /**
      * Test for daylight saving time zone
-     * 
+     *
      * @returns {boolean}
      */
     Date.prototype.isDst = function() {
@@ -71,7 +71,7 @@
                 return;
             }
 
-            this.writeCookie(this.cookieName, timezoneOffset + ',' + dst);
+            this.writeCookie(this.cookieName, timezoneOffset + ',' + Number(dst));
         },
 
         /**