diff --git a/CHANGELOG b/CHANGELOG
index e0aa2ca5..170a6adb 100755
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -12,7 +12,7 @@
 - Added user profile page.
 - Added history tracking of server uptime.
 - Added history graphs of server uptime and latency (thanks to Jérôme Cabanis).
-- Date format is taken from language file and localized per language (thanks to Jérôme Cabanis).
+- Date and time formats are taken from language file and localized per language (thanks to Jérôme Cabanis).
 - When checking a website, the updater will now follow 302 Location headers.
 - String/pattern search on websites did not work for websites with compression turned on.
 - Switched from mysql_* to PDO.
diff --git a/README.md b/README.md
index 72f0852e..cf56a30e 100755
--- a/README.md
+++ b/README.md
@@ -134,7 +134,7 @@ If you would like to contribute a patch or feature, please fork the develop bran
 ### Changing the email or text message
 
 Go to the folder "src/lang", open the language file that corresponds to the selected language
-(default is English ("en.lang.php")). Scroll all the way to the bottom until you spot this line:
+(default is English ("en_US.lang.php")). Scroll all the way to the bottom until you spot this line:
 
      'notifications' => array(
 
diff --git a/src/bootstrap.php b/src/bootstrap.php
index c575fb1c..ffa41336 100755
--- a/src/bootstrap.php
+++ b/src/bootstrap.php
@@ -93,5 +93,5 @@ if($db->status() && (!defined('PSM_INSTALL') || !PSM_INSTALL)) {
 		die();
 	}
 }
-$lang = psm_get_conf('language', 'en');
+$lang = psm_get_conf('language', 'en_US');
 psm_load_lang($lang);
diff --git a/src/includes/functions.inc.php b/src/includes/functions.inc.php
index 505247bb..709a64c3 100755
--- a/src/includes/functions.inc.php
+++ b/src/includes/functions.inc.php
@@ -63,8 +63,8 @@ function psm_load_lang($lang) {
 	$lang_file = PSM_PATH_LANG . $lang . '.lang.php';
 
 	if(!file_exists($lang_file)) {
-		// If the file have been removed, we use the english one
-		$en_file = PSM_PATH_LANG . 'en.lang.php';
+		// If the file has been removed, we use the english one
+		$en_file = PSM_PATH_LANG . 'en_US.lang.php';
 		if(!file_exists($en_file)) {
 			// OK, nothing we can do
 			die('unable to load language file: ' . $lang_file);
@@ -73,10 +73,8 @@ function psm_load_lang($lang) {
 	}
 
 	require $lang_file;
-	if(isset($sm_lang['locale']))
-	{
-		setlocale(LC_TIME, $sm_lang['locale']);
-	}
+	$locale = basename($lang_file, '.lang.php');
+	setlocale(LC_TIME, $locale);
 
 	$GLOBALS['sm_lang'] = $sm_lang;
 }
@@ -98,17 +96,15 @@ function psm_get_langs() {
 		if(file_exists($file)) {
 			require $file;
 		}
-		if(isset($sm_lang['name']))
-		{
+		if(isset($sm_lang['name'])) {
 			$name = $sm_lang['name'];
-		}
-		else
-		{
+		} else {
 			$name = $key;
 		}
 		$langs[$key] = $name;
 		unset($sm_lang);
 	}
+	ksort($langs);
 	return $langs;
 }
 
@@ -274,14 +270,19 @@ function psm_curl_get($href, $header = false, $body = true, $timeout = 10, $add_
  * Source: http://www.interactivetools.com/forum/forum-posts.php?postNum=2208966
  * @param string $time
  * @return string
- * @todo add translation to timespan messages
  */
 function psm_timespan($time) {
-	if(empty($time) || $time == '0000-00-00 00:00:00')
-		return psm_get_lang(system, 'never');
+	if(empty($time) || $time == '0000-00-00 00:00:00') {
+		return psm_get_lang('system', 'never');
+	}
 	if ($time !== intval($time)) { $time = strtotime($time); }
 	if ($time < strtotime(date('Y-m-d 00:00:00')) - 60*60*24*3) {
 		$format = psm_get_lang('system', (date('Y') !== date('Y', $time)) ? 'long_day_format' : 'short_day_format');
+		// Check for Windows to find and replace the %e
+		// modifier correctly
+		if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN') {
+			$format = preg_replace('#(?<!%)((?:%%)*)%e#', '\1%#d', $format);
+		}
 		return strftime($format, $time);
 	}
 	$d = time() - $time;
@@ -302,13 +303,12 @@ function psm_timespan($time) {
  * Get a localised date from MySQL date format
  * @param string $time
  * @return string
- * @todo add translation
  */
-function psm_date($time)
-{
-	if(empty($time) || $time == '0000-00-00 00:00:00')
-		return psm_get_lang(system, 'never');
-	return date(psm_get_lang('system', 'date_time_format'), strtotime($time));
+function psm_date($time) {
+	if(empty($time) || $time == '0000-00-00 00:00:00') {
+		return psm_get_lang('system', 'never');
+	}
+	return strftime('%x %X', strtotime($time));
 }
 
 /**
diff --git a/src/lang/bg.lang.php b/src/lang/bg_BG.lang.php
similarity index 95%
rename from src/lang/bg.lang.php
rename to src/lang/bg_BG.lang.php
index 1696b202..f657e57a 100755
--- a/src/lang/bg.lang.php
+++ b/src/lang/bg_BG.lang.php
@@ -26,8 +26,7 @@
  **/
 
 $sm_lang = array(
-	'name' => 'Български',
-	'locale' => 'bg_BG',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
+	'name' => 'Български - Bulgarian',
 	'system' => array(
 		'title' => 'Server Monitor',
 		'install' => 'Инсталация',
@@ -46,13 +45,11 @@ $sm_lang = array(
 		'update_available' => 'Налична е нова версия. Може да я свалите от <a href="http://www.phpservermonitor.org" target="_blank">тук</a>.',
 		'back_to_top' => 'Нагоре',
 		'go_back' => 'Go back',
-		
-		'date_time_format' => 'd.m.Y H:i:s',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-		
-		'short_day_format' => '%B %e',				// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => '%B %e',
 		'long_day_format' => '%B %e, %Y',
-		'yesterday_format' => 'Yesterday at %l:%Ma',
-		'other_day_format' => '%A at g:ia',
+		'yesterday_format' => 'Yesterday at %k:%M',
+		'other_day_format' => '%A at %k:%M',
 		'never' => 'Never',
 		'hours_ago' => '%d hours ago',
 		'an_hour_ago' => 'about an hour ago',
diff --git a/src/lang/de.lang.php b/src/lang/de_DE.lang.php
similarity index 92%
rename from src/lang/de.lang.php
rename to src/lang/de_DE.lang.php
index e451a1f3..0cafb2f6 100755
--- a/src/lang/de.lang.php
+++ b/src/lang/de_DE.lang.php
@@ -26,8 +26,7 @@
  **/
 
 $sm_lang = array(
-	'name' => 'Dutch',
-	'locale' => 'de_DE',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
+	'name' => 'Deutsch - German',
 	'system' => array(
 		'title' => 'Server Monitor',
 		'install' => 'Install',
@@ -46,13 +45,11 @@ $sm_lang = array(
 		'update_available' => 'Ein neues Update ist verf&uuml;gbar auf <a href="http://www.phpservermonitor.org" target="_blank">http://www.phpservermonitor.org</a>.',
 		'back_to_top' => 'Back to top',
 		'go_back' => 'Go back',
-		
-		'date_time_format' => 'd.m.Y H:i:s',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-		
-		'short_day_format' => '%B %e',				// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => '%B %e',
 		'long_day_format' => '%B %e, %Y',
-		'yesterday_format' => 'Yesterday at %l:%Ma',
-		'other_day_format' => '%A at g:ia',
+		'yesterday_format' => 'Gestern um %k:%M',
+		'other_day_format' => '%A um %k:%M',
 		'never' => 'Never',
 		'hours_ago' => '%d hours ago',
 		'an_hour_ago' => 'about an hour ago',
diff --git a/src/lang/en.lang.php b/src/lang/en_US.lang.php
similarity index 95%
rename from src/lang/en.lang.php
rename to src/lang/en_US.lang.php
index 889dd134..6c591c8e 100755
--- a/src/lang/en.lang.php
+++ b/src/lang/en_US.lang.php
@@ -27,7 +27,6 @@
 
 $sm_lang = array(
 	'name' => 'English',
-	'locale' => 'en_US',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
 	'system' => array(
 		'title' => 'Server Monitor',
 		'install' => 'Install',
@@ -46,13 +45,11 @@ $sm_lang = array(
 		'update_available' => 'A new update is available from <a href="http://www.phpservermonitor.org" target="_blank">http://www.phpservermonitor.org</a>.',
 		'back_to_top' => 'Back to top',
 		'go_back' => 'Go back',
-		
-		'date_time_format' => 'Y-m-d g:i:sa',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-		
-		'short_day_format' => '%B %e',				// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => '%B %e',
 		'long_day_format' => '%B %e, %Y',
-		'yesterday_format' => 'Yesterday at %l:%Ma',
-		'other_day_format' => '%A at g:ia',
+		'yesterday_format' => 'Yesterday at %k:%M',
+		'other_day_format' => '%A at %k:%M',
 		'never' => 'Never',
 		'hours_ago' => '%d hours ago',
 		'an_hour_ago' => 'about an hour ago',
diff --git a/src/lang/fr.lang.php b/src/lang/fr_FR.lang.php
similarity index 94%
rename from src/lang/fr.lang.php
rename to src/lang/fr_FR.lang.php
index 346f435e..6d6a27cb 100755
--- a/src/lang/fr.lang.php
+++ b/src/lang/fr_FR.lang.php
@@ -26,8 +26,7 @@
  **/
 
 $sm_lang = array(
-	'name' => 'Français',
-	'locale' => 'fr_FR',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
+	'name' => 'Français - French',
 	'system' => array(
 		'title' => 'Server Monitor',
 		'install' => 'Installer',
@@ -46,10 +45,8 @@ $sm_lang = array(
 		'update_available' => 'Une nouvelle version est disponible à l\'adresse <a href="http://www.phpservermonitor.org" target="_blank">http://www.phpservermonitor.org</a>.',
 		'back_to_top' => 'Haut de page',
 		'go_back' => 'Retour',
-		
-		'date_time_format' => 'd/m/Y H:i:s',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-
-		'short_day_format' => 'Le %e %B',			// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => 'Le %e %B',
 		'long_day_format' => 'Le %e %B %Y',
 		'yesterday_format' => 'Hier à %kh%M',
 		'other_day_format' => '%A à %kh%M',
diff --git a/src/lang/kr.lang.php b/src/lang/ko_KR.lang.php
similarity index 92%
rename from src/lang/kr.lang.php
rename to src/lang/ko_KR.lang.php
index 4ed6e44f..08879fa3 100755
--- a/src/lang/kr.lang.php
+++ b/src/lang/ko_KR.lang.php
@@ -26,8 +26,7 @@
  **/
 
 $sm_lang = array(
-	'name' => '한국',
-	'locale' => 'ko_KR',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
+	'name' => '한국 - Korean',
 	'system' => array(
 		'title' => 'Server Monitor',
 		'install' => 'Install',
@@ -46,13 +45,11 @@ $sm_lang = array(
 		'update_available' => '새로운 업데이트가 있습니다. 다음사이트를 방문 해 주십시오. <a href="http://www.phpservermonitor.org" target="_blank">http://www.phpservermonitor.org</a>.',
 		'back_to_top' => 'Back to top',
 		'go_back' => 'Go back',
-		
-		'date_time_format' => 'Y-m-d H:i:s',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-		
-		'short_day_format' => '%B %e',				// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => '%B %e',
 		'long_day_format' => '%B %e, %Y',
-		'yesterday_format' => 'Yesterday at %l:%Ma',
-		'other_day_format' => '%A at g:ia',
+		'yesterday_format' => 'Yesterday at %X',
+		'other_day_format' => '%A at %X',
 		'never' => 'Never',
 		'hours_ago' => '%d hours ago',
 		'an_hour_ago' => 'about an hour ago',
diff --git a/src/lang/nl.lang.php b/src/lang/nl_NL.lang.php
similarity index 89%
rename from src/lang/nl.lang.php
rename to src/lang/nl_NL.lang.php
index 4d44e03f..d9750c21 100755
--- a/src/lang/nl.lang.php
+++ b/src/lang/nl_NL.lang.php
@@ -26,8 +26,7 @@
  **/
 
 $sm_lang = array(
-	'name' => 'Nederlands',
-	'locale' => 'nl_NL',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
+	'name' => 'Nederlands - Dutch',
 	'system' => array(
 		'title' => 'Server Monitor',
 		'install' => 'Install',
@@ -46,25 +45,23 @@ $sm_lang = array(
 		'update_available' => 'Een nieuwe update is beschikbaar op <a href="http://www.phpservermonitor.org" target="_blank">http://www.phpservermonitor.org</a>.',
 		'back_to_top' => 'Terug naar boven',
 		'go_back' => 'Terug',
-		
-		'date_time_format' => 'd-m-Y H:i:s',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-		
-		'short_day_format' => '%B %e',				// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => '%B %e',
 		'long_day_format' => '%B %e, %Y',
-		'yesterday_format' => 'Yesterday at %l:%Ma',
-		'other_day_format' => '%A at g:ia',
-		'never' => 'Never',
-		'hours_ago' => '%d hours ago',
-		'an_hour_ago' => 'about an hour ago',
-		'minutes_ago' => '%d minutes ago',
-		'a_minute_ago' => 'about a minute ago',
-		'seconds_ago' => '%d seconds ago',
-		'a_second_ago' => 'a second ago',
+		'yesterday_format' => 'Gisteren om %k:%M',
+		'other_day_format' => '%A om %k:%M',
+		'never' => 'Nooit',
+		'hours_ago' => '%d uren geleden',
+		'an_hour_ago' => 'een uur geleden',
+		'minutes_ago' => '%d minuten geleden',
+		'a_minute_ago' => 'een minuut geleden',
+		'seconds_ago' => '%d seconden geleden',
+		'a_second_ago' => 'een seconde geleden',
 	),
 	'menu' => array(
 		'config' => 'Config',
 		'server' => 'Servers',
-		'server_history' => 'History',
+		'server_history' => 'Geschiedenis',
 		'server_log' => 'Log',
 		'server_status' => 'Status',
 		'server_update' => 'Update',
@@ -114,7 +111,7 @@ $sm_lang = array(
 		'type_website' => 'Website',
 		'type_service' => 'Service',
 		'pattern' => 'Zoek voor tekst/regex',
-		'pattern_description' => 'If this pattern is not found on the website, the server will be marked offline. Regular expressions are allowed.',
+		'pattern_description' => 'Als dit patroon niet gevonden wordt op de website, zal de server als offline gemarkeerd worden. Regular expressions zijn toegestaan.',
 		'last_check' => 'Laatst gecontroleerd',
 		'last_online' => 'Laatst online',
 		'monitoring' => 'Monitoring',
@@ -128,7 +125,7 @@ $sm_lang = array(
 		'day' => 'Day',
 		'hour' => 'Hour',
 		'warning_threshold' => 'Warning threshold',
-		'warning_threshold_description' => 'Number of failed checks required before it is marked offline.',
+		'warning_threshold_description' => 'Aantal mislukte pogingen voordat de server als offline gemarkeerd wordt.',
 
 		// Charts date format according jqPlot date format  http://www.jqplot.com/docs/files/plugins/jqplot-dateAxisRenderer-js.html
 		'chart_long_date_format' => '%d-%m-%Y %H:%M:%S',
diff --git a/src/lang/br.lang.php b/src/lang/pt_BR.lang.php
similarity index 95%
rename from src/lang/br.lang.php
rename to src/lang/pt_BR.lang.php
index d1b00502..04734b97 100755
--- a/src/lang/br.lang.php
+++ b/src/lang/pt_BR.lang.php
@@ -26,8 +26,7 @@
  **/
 
 $sm_lang = array(
-	'name' => 'Portugês - Brasil',
-	'locale' => 'pt_BR',					// Language code (ISO 639-1) + Contry code (ISO_3166-1)
+	'name' => 'Português - Brazilian portuguese',
     'system' => array(
         'title' => 'Server Monitor',
 		'install' => 'Install',
@@ -46,13 +45,11 @@ $sm_lang = array(
         'update_available' => 'Uma atualização disponível em <a href="http://www.phpservermonitor.org" target="_blank">http://www.phpservermonitor.org</a>.',
         'back_to_top' => 'Voltar ao topo',
 		'go_back' => 'Go back',
-		
-		'date_time_format' => 'd/m/Y H:i:s',		// date/time format according the date php function format parameter http://php.net/manual/function.date.php
-		
-		'short_day_format' => '%B %e',				// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		// date/time format according the strftime php function format parameter http://php.net/manual/function.strftime.php
+		'short_day_format' => '%B %e',
 		'long_day_format' => '%B %e, %Y',
-		'yesterday_format' => 'Yesterday at %l:%Ma',
-		'other_day_format' => '%A at g:ia',
+		'yesterday_format' => 'Yesterday at %k:%M',
+		'other_day_format' => '%A at %k:%M',
 		'never' => 'Never',
 		'hours_ago' => '%d hours ago',
 		'an_hour_ago' => 'about an hour ago',
diff --git a/src/psm/Util/Install/Installer.class.php b/src/psm/Util/Install/Installer.class.php
index 0f6caaa0..19c05504 100755
--- a/src/psm/Util/Install/Installer.class.php
+++ b/src/psm/Util/Install/Installer.class.php
@@ -248,6 +248,15 @@ class Installer {
 	 */
 	protected function upgrade220() {
 		$queries = array();
+		// language is now stored as language code (ISO 639-1) + country code (ISO 3166-1)
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='bg_BG' WHERE `key`='language' AND `value`='bg';";
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='de_DE' WHERE `key`='language' AND `value`='de';";
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='en_US' WHERE `key`='language' AND `value`='en';";
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='fr_FR' WHERE `key`='language' AND `value`='fr';";
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='ko_KR' WHERE `key`='language' AND `value`='kr';";
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='nl_NL' WHERE `key`='language' AND `value`='nl';";
+		$queries[] = "UPDATE `" . PSM_DB_PREFIX . "config` SET `value`='pt_BR' WHERE `key`='language' AND `value`='br';";
+
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "log` CHANGE `log_id` `log_id` INT( 11 ) UNSIGNED NOT NULL AUTO_INCREMENT;";
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "log` CHANGE `server_id` `server_id` INT( 11 ) UNSIGNED NOT NULL;";