diff --git a/src/includes/functions.inc.php b/src/includes/functions.inc.php
index 2670a12e..dde0f585 100644
--- a/src/includes/functions.inc.php
+++ b/src/includes/functions.inc.php
@@ -278,6 +278,25 @@ function psm_log_uptime($server_id, $status, $latency) {
 	);
 }
 
+/**
+ * Converts an interval into a string
+ *
+ * @param DateInterval $interval
+ * @return string
+ */
+ function psm_format_interval(DateInterval $interval) {
+    $result = "";
+
+    if ($interval->y) { $result .= $interval->format("%y ") . ( ($interval->y == 1)  ? psm_get_lang('system', 'year') : psm_get_lang('system', 'years') ) . " "; }
+    if ($interval->m) { $result .= $interval->format("%m ") . ( ($interval->m == 1)  ? psm_get_lang('system', 'month') : psm_get_lang('system', 'months') ) . " "; }
+    if ($interval->d) { $result .= $interval->format("%d ") . ( ($interval->d == 1)  ? psm_get_lang('system', 'day') : psm_get_lang('system', 'days') ) . " "; }
+    if ($interval->h) { $result .= $interval->format("%h ") . ( ($interval->h == 1)  ? psm_get_lang('system', 'hour') : psm_get_lang('system', 'hours') ) . " "; }
+    if ($interval->i) { $result .= $interval->format("%i ") . ( ($interval->i == 1)  ? psm_get_lang('system', 'minute') : psm_get_lang('system', 'minutes') ) . " "; }
+    if ($interval->s) { $result .= $interval->format("%s ") . ( ($interval->s == 1)  ? psm_get_lang('system', 'second') : psm_get_lang('system', 'seconds') ) . " "; }
+
+    return $result;
+}
+
 /**
  * Parses a string from the language file with the correct variables replaced in the message
  *
diff --git a/src/lang/bg_BG.lang.php b/src/lang/bg_BG.lang.php
index 1b4f4599..ee5b11c2 100644
--- a/src/lang/bg_BG.lang.php
+++ b/src/lang/bg_BG.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'преди минута',
 		'seconds_ago' => 'преди %d секунди',
 		'a_second_ago' => 'преди секунда',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Настройки',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'Ако този текст не е намерен в интернет страницата (когато имате добавен сайт), той ще бъде маркиран като Офлайн. Регулярните изрази са разрешени.',
 		'last_check' => 'Последна проверка',
 		'last_online' => 'Последно на линия',
+		'last_offline' => 'Last offline',
 		'monitoring' => 'Мониторинг',
 		'no_monitoring' => 'Не се наблюдава',
 		'email' => 'Имейл',
diff --git a/src/lang/cs_CZ.lang.php b/src/lang/cs_CZ.lang.php
index 6d721b54..fd3a8fbf 100644
--- a/src/lang/cs_CZ.lang.php
+++ b/src/lang/cs_CZ.lang.php
@@ -61,6 +61,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'cca před minutou',
 		'seconds_ago' => 'před %d vteřinami',
 		'a_second_ago' => 'před chvílí',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Konfigurace',
@@ -143,6 +155,7 @@ $sm_lang = array(
 		'pattern_description' => 'Pokud vzorek nebude na webu nalezen, bude server označen jako offline. Regulární výrazy jsou povoleny.',
 		'last_check' => 'Poslední kontrola',
 		'last_online' => 'Naposledy online',
+		'last_offline' => 'Naposledy offline',
 		'monitoring' => 'Monitoring',
 		'no_monitoring' => 'Žádné monitorované služby',
 		'email' => 'E-mail',
diff --git a/src/lang/da_DK.lang.php b/src/lang/da_DK.lang.php
index efa54f53..cfa62017 100644
--- a/src/lang/da_DK.lang.php
+++ b/src/lang/da_DK.lang.php
@@ -58,6 +58,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'omkring et minut siden',
 		'seconds_ago' => '%d sekunder siden',
 		'a_second_ago' => 'et sekund siden',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Indstillinger',
@@ -130,6 +142,7 @@ $sm_lang = array(
 		'pattern_description' => 'Hvis dette mønster ikke findes på hjemmesiden, vil serveren blive markeret som værende offline. Regulære udtryk er tilladt.',
 		'last_check' => 'Sidst kontrolleret',
 		'last_online' => 'Sidst online',
+		'last_offline' => 'Sidst offline',
 		'monitoring' => 'Overvågning',
 		'no_monitoring' => 'Ingen overvågning',
 		'email' => 'E-mail',
diff --git a/src/lang/de_DE.lang.php b/src/lang/de_DE.lang.php
index 818b1876..b4094b07 100644
--- a/src/lang/de_DE.lang.php
+++ b/src/lang/de_DE.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'vor über einer Minute',
 		'seconds_ago' => 'vor %d Sekunden',
 		'a_second_ago' => 'vor über einer Sekunde',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Einstellungen',
@@ -133,6 +145,7 @@ $sm_lang = array(
 		'pattern_description' => 'Wenn das gesuchte Muster nicht in der Webseite ist, wird die Seite als offline markiert. Reguläre Ausdrücke sind erlaubt.',
 		'last_check' => 'Letzter Check',
 		'last_online' => 'Zuletzt online',
+		'last_offline' => 'Zuletzt offline',
 		'monitoring' => 'Monitoring',
 		'no_monitoring' => 'Monitoring inaktiv',
 		'email' => 'E-Mail',
diff --git a/src/lang/en_US.lang.php b/src/lang/en_US.lang.php
index 68844d61..29c0697c 100644
--- a/src/lang/en_US.lang.php
+++ b/src/lang/en_US.lang.php
@@ -61,6 +61,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'about a minute ago',
 		'seconds_ago' => '%d seconds ago',
 		'a_second_ago' => 'a second ago',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Config',
@@ -158,6 +170,7 @@ $sm_lang = array(
 		'header_value_description' => 'Header value. Regular expressions are allowed.',
 		'last_check' => 'Last check',
 		'last_online' => 'Last online',
+		'last_offline' => 'Last offline',
 		'monitoring' => 'Monitoring',
 		'no_monitoring' => 'No monitoring',
 		'email' => 'Email',
@@ -325,12 +338,12 @@ $sm_lang = array(
 		'off_pushover_title' => 'Server \'%LABEL%\' is DOWN',
 		'off_pushover_message' => "Failed to connect to the following server:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Error: %ERROR%<br/>Date: %DATE%",
 		'off_telegram_message' => "Failed to connect to the following server:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Error: %ERROR%<br/>Date: %DATE%",
-		'on_sms' => 'Server \'%LABEL%\' is RUNNING: ip=%IP%, port=%PORT%',
+		'on_sms' => 'Server \'%LABEL%\' is RUNNING: ip=%IP%, port=%PORT%, it was down for %LAST_OFFLINE_DURATION%',
 		'on_email_subject' => 'IMPORTANT: Server \'%LABEL%\' is RUNNING',
-		'on_email_body' => "Server '%LABEL%' is running again:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Date: %DATE%",
+		'on_email_body' => "Server '%LABEL%' is running again, it was down for %LAST_OFFLINE_DURATION%:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Date: %DATE%",
 		'on_pushover_title' => 'Server \'%LABEL%\' is RUNNING',
-		'on_pushover_message' => 'Server \'%LABEL%\' is running again:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Date: %DATE%',
-		'on_telegram_message' => 'Server \'%LABEL%\' is running again:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Date: %DATE%',
+		'on_pushover_message' => 'Server \'%LABEL%\' is running again, it was down for %LAST_OFFLINE_DURATION%:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Date: %DATE%',
+		'on_telegram_message' => 'Server \'%LABEL%\' is running again, it was down for %LAST_OFFLINE_DURATION%:<br/><br/>Server: %LABEL%<br/>IP: %IP%<br/>Port: %PORT%<br/>Date: %DATE%',
 	),
 	'login' => array(
 		'welcome_usermenu' => 'Welcome, %user_name%',
diff --git a/src/lang/es_ES.lang.php b/src/lang/es_ES.lang.php
index 4e1534d3..aab8ac56 100644
--- a/src/lang/es_ES.lang.php
+++ b/src/lang/es_ES.lang.php
@@ -62,6 +62,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'Hace aproximadamente un minuto',
 		'seconds_ago' => 'Hace %d segundos',
 		'a_second_ago' => 'Hace aproximadamente un segundo',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Configurar',
@@ -134,6 +146,7 @@ $sm_lang = array(
 		'pattern_description' => 'Si este patrón no se encuentra en el sitio web, el servidor estará marcada como sin conexión. Se permiten expresiones regulares.',
 		'last_check' => 'Última verificación',
 		'last_online' => 'Última vez en línea',
+		'last_offline' => 'Last offline',
 		'monitoring' => 'Monitoreo',
 		'no_monitoring' => 'Sin monitoreo',
 		'email' => 'Email',
diff --git a/src/lang/fr_FR.lang.php b/src/lang/fr_FR.lang.php
index be70cf5d..ab97767c 100644
--- a/src/lang/fr_FR.lang.php
+++ b/src/lang/fr_FR.lang.php
@@ -61,6 +61,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'Il y a une minute',
 		'seconds_ago' => 'Il y a %d secondes',
 		'a_second_ago' => 'Il y a une seconde',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Configuration',
@@ -133,6 +145,7 @@ $sm_lang = array(
 		'pattern_description' => 'Si ce texte n\'est par retrouvé sur le site web, le serveur est marqué hors-service. Les expressions réguliaires sont autorisées.',
 		'last_check' => 'Dernière vérification',
 		'last_online' => 'Dernière fois OK',
+		'last_offline' => 'Last offline',
 		'monitoring' => 'Surveillé',
 		'no_monitoring' => 'Non surveillé',
 		'email' => 'Email',
diff --git a/src/lang/it_IT.lang.php b/src/lang/it_IT.lang.php
index 2396b8dc..4de13b52 100644
--- a/src/lang/it_IT.lang.php
+++ b/src/lang/it_IT.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'circa un minuto fa',
 		'seconds_ago' => '%d secondi fa',
 		'a_second_ago' => 'un secondo fa',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Configurazione',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'Se questo pattern non è trovato nel sito web, il server verrà contrassegnato come fuori linea. Le espressioni regolari sono consentite.',
 		'last_check' => 'Ultimo Controllo',
 		'last_online' => 'Ultima volta Online',
+		'last_offline' => 'Ultima volta offline',
 		'monitoring' => 'Monitoraggio',
 		'no_monitoring' => 'Non monitorato',
 		'email' => 'Email',
diff --git a/src/lang/ko_KR.lang.php b/src/lang/ko_KR.lang.php
index b04b6348..10341ef0 100644
--- a/src/lang/ko_KR.lang.php
+++ b/src/lang/ko_KR.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'about a minute ago',
 		'seconds_ago' => '%d seconds ago',
 		'a_second_ago' => 'a second ago',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => '설정',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'If this pattern is not found on the website, the server will be marked offline. Regular expressions are allowed.',
 		'last_check' => '최근체크',
 		'last_online' => '최근접속',
+		'last_offline' => 'Last offline',
 		'monitoring' => '확인중',
 		'no_monitoring' => 'No monitoring',
 		'email' => '메일 전송',
diff --git a/src/lang/nl_NL.lang.php b/src/lang/nl_NL.lang.php
index fa5852fe..110e4e69 100644
--- a/src/lang/nl_NL.lang.php
+++ b/src/lang/nl_NL.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'een minuut geleden',
 		'seconds_ago' => '%d seconden geleden',
 		'a_second_ago' => 'een seconde geleden',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Configuratie',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'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',
+		'last_offline' => 'Laatst offline',
 		'monitoring' => 'Monitoring',
 		'no_monitoring' => 'Geen monitoring',
 		'email' => 'Email',
diff --git a/src/lang/pl_PL.lang.php b/src/lang/pl_PL.lang.php
index d3e8481a..853d3f3c 100644
--- a/src/lang/pl_PL.lang.php
+++ b/src/lang/pl_PL.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'minutę temu',
 		'seconds_ago' => '%d sekund temu',
 		'a_second_ago' => 'sekundę temu',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Konfiguracja',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'Jeśli wzorzec nie zostanie odnaleziony, status zostanie ustawiony na  offline. Wyrażenia regularne są dozwolone.',
 		'last_check' => 'Ostatnie sprawdzenie',
 		'last_online' => 'Ostatnio online',
+		'last_offline' => 'Ostatnio offline',
 		'monitoring' => 'Monitorowany',
 		'no_monitoring' => 'Brak monitoringu',
 		'email' => 'Email',
diff --git a/src/lang/pt_BR.lang.php b/src/lang/pt_BR.lang.php
index c52c487e..26e51f85 100644
--- a/src/lang/pt_BR.lang.php
+++ b/src/lang/pt_BR.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'cerca de um minuto atrás',
 		'seconds_ago' => '%d segundos atrás',
 		'a_second_ago' => 'um segundo atrás',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
     ),
 	'menu' => array(
 		'config' => 'Configuração',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'Se esse padrão não for encontrado no site, o servidor será marcado offline. As expressões regulares são permitidas.',
         'last_check' => 'Última verificação',
         'last_online' => 'Última vez online',
+		'last_offline' => 'Última vez offline',
         'monitoring' => 'Monitoramento',
 		'no_monitoring' => 'Sem monitoring',
         'email' => 'Email',
diff --git a/src/lang/ru_RU.lang.php b/src/lang/ru_RU.lang.php
index 886efb13..4825e56e 100644
--- a/src/lang/ru_RU.lang.php
+++ b/src/lang/ru_RU.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'минуту назад',
 		'seconds_ago' => '%d секунд назад',
 		'a_second_ago' => 'секунду назад',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Параметры',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'Если текст по шаблону не найден на сайте, сервер будет помечен как Оффлайн. Регулярные выражения допустимы.',
 		'last_check' => 'Последняя проверка',
 		'last_online' => 'Был онлайн',
+		'last_offline' => 'Last offline',
 		'monitoring' => 'Мониторинг',
 		'no_monitoring' => 'Нет мониторинга',
 		'email' => 'E-mail',
diff --git a/src/lang/sv_SE.lang.php b/src/lang/sv_SE.lang.php
index a79e89e1..9d750e48 100644
--- a/src/lang/sv_SE.lang.php
+++ b/src/lang/sv_SE.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => 'ungefär en minut sen',
 		'seconds_ago' => '%d sekunder sedan',
 		'a_second_ago' => 'en sekund sedan',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => 'Inställningar',
@@ -132,6 +144,7 @@ $sm_lang = array(
 		'pattern_description' => 'Om detta mönster inte hittas i svaret kommer servern att markeras offline. "Regular expressions" är tillåtna.',
 		'last_check' => 'Senaste kontroll',
 		'last_online' => 'Senast online',
+		'last_offline' => 'Senast offline',
 		'monitoring' => 'Övervakas',
 		'no_monitoring' => 'Övervakas inte',
 		'email' => 'Email',
diff --git a/src/lang/tr_TR.lang.php b/src/lang/tr_TR.lang.php
index 43ab1e99..e5e498fd 100644
--- a/src/lang/tr_TR.lang.php
+++ b/src/lang/tr_TR.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
         'a_minute_ago' => 'yaklaşık bir dakika önce',
         'seconds_ago' => '%d saniye önce',
         'a_second_ago' => 'bir saniye önce',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
     ),
     'menu' => array(
         'config' => 'Ayarlar',
@@ -132,6 +144,7 @@ $sm_lang = array(
         'pattern_description' => 'Bu pattern web sitenizde bulunamaz ise, sunucu offline olarak işaretlenecek. Regular expression\'a izin verilmiştir.',
         'last_check' => 'Son kontrol',
         'last_online' => 'Son çevrimiçi zamanı',
+        'last_offline' => 'Last offline',
         'monitoring' => 'Monitoring',
         'no_monitoring' => 'No monitoring',
         'email' => 'E-posta',
diff --git a/src/lang/zh_CN.lang.php b/src/lang/zh_CN.lang.php
index 736def15..0421d8a6 100644
--- a/src/lang/zh_CN.lang.php
+++ b/src/lang/zh_CN.lang.php
@@ -60,6 +60,18 @@ $sm_lang = array(
 		'a_minute_ago' => '1分钟前',
 		'seconds_ago' => '%d 秒前',
 		'a_second_ago' => '刚刚',
+		'year' => 'year',
+		'years' => 'years',
+		'month' => 'month',
+		'months' => 'months',
+		'day' => 'day',
+		'days' => 'days',
+		'hour' => 'hour',
+		'hours' => 'hours',
+		'minute' => 'minute',
+		'minutes' => 'minutes',
+		'second' => 'second',
+		'seconds' => 'seconds',
 	),
 	'menu' => array(
 		'config' => '设置',
@@ -142,6 +154,7 @@ $sm_lang = array(
 		'pattern_description' => '如果在网站上未找到对应匹配内容, 则标记该网站为离线. 支持正则表达式.',
 		'last_check' => '最后检查',
 		'last_online' => '最后在线',
+		'last_offline' => 'Last offline',
 		'monitoring' => '监控',
 		'no_monitoring' => '未监控',
 		'email' => '邮件',
diff --git a/src/psm/Module/Server/Controller/AbstractServerController.php b/src/psm/Module/Server/Controller/AbstractServerController.php
index 8aa0020c..d4bfe48c 100644
--- a/src/psm/Module/Server/Controller/AbstractServerController.php
+++ b/src/psm/Module/Server/Controller/AbstractServerController.php
@@ -71,6 +71,8 @@ abstract class AbstractServerController extends AbstractController {
 					`s`.`rtime`,
 					`s`.`last_check`,
 					`s`.`last_online`,
+					`s`.`last_offline`,
+					`s`.`last_offline_duration`,
 					`s`.`active`,
 					`s`.`email`,
 					`s`.`sms`,
@@ -102,6 +104,13 @@ abstract class AbstractServerController extends AbstractController {
 	protected function formatServer($server) {
 		$server['rtime'] = round((float) $server['rtime'], 4);
 		$server['last_online']  = psm_timespan($server['last_online']);
+		$server['last_offline']  = psm_timespan($server['last_offline']);
+		if ($server['last_offline'] != psm_get_lang('system', 'never')) {
+			$server['last_offline_duration'] = "(".$server['last_offline_duration'].")";
+		}
+		else {
+			$server['last_offline_duration'] = "";
+		}
 		$server['last_check']  = psm_timespan($server['last_check']);
 		$server['active'] = psm_get_lang('system', $server['active']);
 		$server['email'] = psm_get_lang('system', $server['email']);
diff --git a/src/psm/Module/Server/Controller/ServerController.php b/src/psm/Module/Server/Controller/ServerController.php
index 4d665295..6419ad1e 100644
--- a/src/psm/Module/Server/Controller/ServerController.php
+++ b/src/psm/Module/Server/Controller/ServerController.php
@@ -477,6 +477,7 @@ class ServerController extends AbstractServerController {
 			'label_last_check' => psm_get_lang('servers', 'last_check'),
 			'label_rtime' => psm_get_lang('servers', 'latency'),
 			'label_last_online' => psm_get_lang('servers', 'last_online'),
+			'label_last_offline' => psm_get_lang('servers', 'last_offline'),
 			'label_monitoring' => psm_get_lang('servers', 'monitoring'),
 			'label_email' => psm_get_lang('servers', 'email'),
 			'label_send_email' => psm_get_lang('servers', 'send_email'),
diff --git a/src/psm/Module/Server/Controller/StatusController.php b/src/psm/Module/Server/Controller/StatusController.php
index 2d72a154..12c3ba2f 100644
--- a/src/psm/Module/Server/Controller/StatusController.php
+++ b/src/psm/Module/Server/Controller/StatusController.php
@@ -55,6 +55,7 @@ class StatusController extends AbstractServerController {
 		$layout_data = array(
 			'label_last_check' => psm_get_lang('servers', 'last_check'),
 			'label_last_online' => psm_get_lang('servers', 'last_online'),
+			'label_last_offline' => psm_get_lang('servers', 'last_offline'),
 			'label_rtime' => psm_get_lang('servers', 'latency'),
 			'block_layout_active'	=> ($layout == 0) ? 'active' : '',
 			'list_layout_active'	=> ($layout != 0) ? 'active' : '',
@@ -75,6 +76,11 @@ class StatusController extends AbstractServerController {
 			}
 			$server['last_checked_nice'] = psm_timespan($server['last_check']);
 			$server['last_online_nice'] = psm_timespan($server['last_online']);
+			$server['last_offline_nice'] = psm_timespan($server['last_offline']);
+			$server['last_offline_duration_nice'] = "";
+			if ($server['last_offline_nice'] != psm_get_lang('system', 'never')) {
+				$server['last_offline_duration_nice'] = "(".$server['last_offline_duration'].")";
+			}
 			$server['url_view'] = psm_build_url(array('mod' => 'server', 'action' => 'view', 'id' => $server['server_id'], 'back_to' => 'server_status'));
 
 			if ($server['status'] == "off") {
diff --git a/src/psm/Util/Install/Installer.php b/src/psm/Util/Install/Installer.php
index 691fe31a..0743199c 100644
--- a/src/psm/Util/Install/Installer.php
+++ b/src/psm/Util/Install/Installer.php
@@ -234,16 +234,18 @@ class Installer {
 						  `error` varchar(255) NULL,
 						  `rtime` FLOAT(9, 7) NULL,
 						  `last_online` datetime NULL,
+						  `last_offline` datetime NULL,
+						  `last_offline_duration` varchar(255) NULL,
 						  `last_check` datetime NULL,
 						  `active` enum('yes','no') NOT NULL default 'yes',
 						  `email` enum('yes','no') NOT NULL default 'yes',
 						  `sms` enum('yes','no') NOT NULL default 'no',
 						  `pushover` enum('yes','no') NOT NULL default 'yes',
-							`telegram` enum('yes','no') NOT NULL default 'yes',
-              `warning_threshold` mediumint(1) unsigned NOT NULL DEFAULT '1',
-              `warning_threshold_counter` mediumint(1) unsigned NOT NULL DEFAULT '0',
-              `timeout` smallint(1) unsigned NULL DEFAULT NULL,
-              `website_username` varchar(255) DEFAULT NULL,
+						  `telegram` enum('yes','no') NOT NULL default 'yes',
+			              `warning_threshold` mediumint(1) unsigned NOT NULL DEFAULT '1',
+			              `warning_threshold_counter` mediumint(1) unsigned NOT NULL DEFAULT '0',
+			              `timeout` smallint(1) unsigned NULL DEFAULT NULL,
+			              `website_username` varchar(255) DEFAULT NULL,
 						  `website_password` varchar(255) DEFAULT NULL,
 						  PRIMARY KEY  (`server_id`)
 						) ENGINE=MyISAM  DEFAULT CHARSET=utf8;",
@@ -307,6 +309,9 @@ class Installer {
 		if(version_compare($version_from, '3.2.2', '<')) {
 			$this->upgrade322();
 		}
+		if(version_compare($version_from, '3.3.0', '<')) {
+			$this->upgrade330();
+		}
 		psm_update_conf('version', $version_to);
 	}
 
@@ -326,6 +331,8 @@ class Installer {
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` CHANGE `last_online` `last_online` DATETIME NULL;";
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` CHANGE `last_check` `last_check` DATETIME NULL;";
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `pattern` VARCHAR( 255 ) NOT NULL AFTER  `type`;";
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `last_offline` DATETIME NULL;";
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `last_offline_duration` varchar(255) NULL;";
 
 		$this->execSQL($queries);
 	}
@@ -357,6 +364,8 @@ class Installer {
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` CHANGE `server_id` `server_id` INT( 11 ) UNSIGNED NOT NULL AUTO_INCREMENT;";
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD `warning_threshold` MEDIUMINT( 1 ) UNSIGNED NOT NULL DEFAULT '1';";
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD `warning_threshold_counter` MEDIUMINT( 1 ) UNSIGNED NOT NULL DEFAULT '0';";
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `last_offline` DATETIME NULL;";
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `last_offline_duration` varchar(255) NULL;";
 
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "users` CHANGE `user_id` `user_id` INT( 11 ) UNSIGNED NOT NULL AUTO_INCREMENT;";
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "users`
@@ -439,6 +448,8 @@ class Installer {
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "log` CHANGE `type` `type` ENUM( 'status', 'email', 'sms', 'pushover' ) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;";
 
 		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD `timeout` smallint(1) unsigned NULL DEFAULT NULL;";
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `last_offline` DATETIME NULL;";
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD  `last_offline_duration` varchar(255) NULL;";
 
 		$queries[] = "CREATE TABLE IF NOT EXISTS `" . PSM_DB_PREFIX . "users_preferences` (
 						`user_id` int(11) unsigned NOT NULL,
@@ -515,4 +526,13 @@ class Installer {
 					('telegram_api_token', '');";
 		$this->execSQL($queries);
 	}
+
+	/**
+	 * Upgrade for v3.3.0 release
+	 */
+	protected function upgrade330() {
+		$queries = array();
+		$queries[] = "ALTER TABLE `" . PSM_DB_PREFIX . "servers` ADD COLUMN `last_offline` DATETIME NULL AFTER `last_online`, ADD COLUMN `last_offline_duration` varchar(255) NULL AFTER `last_offline`;";
+		$this->execSQL($queries);
+	}
 }
diff --git a/src/psm/Util/Server/Updater/StatusNotifier.php b/src/psm/Util/Server/Updater/StatusNotifier.php
index aa5adf3d..33fe8129 100644
--- a/src/psm/Util/Server/Updater/StatusNotifier.php
+++ b/src/psm/Util/Server/Updater/StatusNotifier.php
@@ -128,7 +128,7 @@ class StatusNotifier {
 		$this->server = $this->db->selectRow(PSM_DB_PREFIX . 'servers', array(
 			'server_id' => $server_id,
 		), array(
-			'server_id', 'ip', 'port', 'label', 'type', 'pattern', 'status', 'header_name', 'header_value', 'error', 'active', 'email', 'sms', 'pushover', 'telegram',
+			'server_id', 'ip', 'port', 'label', 'type', 'pattern', 'status', 'header_name', 'header_value', 'error', 'active', 'email', 'sms', 'pushover', 'telegram', 'last_online', 'last_offline', 'last_offline_duration',
 		));
 		if(empty($this->server)) {
 			return false;
diff --git a/src/psm/Util/Server/Updater/StatusUpdater.php b/src/psm/Util/Server/Updater/StatusUpdater.php
index e336f2e2..10e2fe4e 100644
--- a/src/psm/Util/Server/Updater/StatusUpdater.php
+++ b/src/psm/Util/Server/Updater/StatusUpdater.php
@@ -83,7 +83,7 @@ class StatusUpdater {
 			'server_id' => $server_id,
 		), array(
 			'server_id', 'ip', 'port', 'label', 'type', 'pattern', 'header_name', 'header_value', 'status', 'active', 'warning_threshold',
-			'warning_threshold_counter', 'timeout', 'website_username', 'website_password'
+			'warning_threshold_counter', 'timeout', 'website_username', 'website_password', 'last_offline'
 		));
 		if(empty($this->server)) {
 			return false;
@@ -117,6 +117,12 @@ class StatusUpdater {
 			$save['status'] = 'on';
 			$save['last_online'] = date('Y-m-d H:i:s');
 			$save['warning_threshold_counter'] = 0;
+			if ($this->server['status'] == 'off') {
+				$online_date = new \DateTime($save['last_online']);
+				$offline_date = new \DateTime($this->server['last_offline']);
+				$difference = $online_date->diff($offline_date);
+				$save['last_offline_duration'] = trim(psm_format_interval($difference));
+			}
 		} else {
 			// server is offline, increase the error counter
 			$save['warning_threshold_counter'] = $this->server['warning_threshold_counter'] + 1;
@@ -128,6 +134,9 @@ class StatusUpdater {
 				$this->status_new = true;
 			} else {
 				$save['status'] = 'off';
+				if ($this->server['status'] == 'on') {
+					$save['last_offline'] = $save['last_check'];
+				}
 			}
 		}
 
diff --git a/src/templates/default/module/server/server/list.tpl.html b/src/templates/default/module/server/server/list.tpl.html
index ed5d7ae3..9ab2ec66 100644
--- a/src/templates/default/module/server/server/list.tpl.html
+++ b/src/templates/default/module/server/server/list.tpl.html
@@ -8,6 +8,7 @@
 			<th class="visible-desktop">{{ label_type }}</th>
 			<th class="hidden-phone">{{ label_rtime }}</th>
 			<th class="hidden-phone">{{ label_last_online }}</th>
+			<th class="hidden-phone">{{ label_last_offline }}</th>
 			<th class="hidden-phone">{{ label_monitoring }}</th>
 			<th class="hidden-phone">{{ label_action }}</th>
 		</tr>
@@ -23,6 +24,7 @@
 			<td class="nowrap visible-desktop"><div class="table-cell-title">{{ server.type }}</div></td>
 			<td class="nowrap hidden-phone"><div class="table-cell-title">{{ server.rtime }} s</div></td>
 			<td class="nowrap hidden-phone"><div class="table-cell-title">{{ server.last_online }}</div></td>
+			<td class="nowrap hidden-phone"><div class="table-cell-title">{{ server.last_offline }} {{ server.last_offline_duration }}</div></td>
 			<td class="tight hidden-phone">
 				<div class="table-cell-title">
 					<i class="{{ server.active_icon }}" title="{{ server.active_title }}"></i>
@@ -70,6 +72,7 @@
 				<div class="table-body">
 					<div class="table-row"><div class="table-cell-details tight">{{ label_rtime }}: &nbsp;</div><div class="table-cell-details">{{ server.rtime }} s</div></div>
 					<div class="table-row"><div class="table-cell-details tight">{{ label_last_online }}: &nbsp;</div><div class="table-cell-details">{{ server.last_online }}</div></div>
+					<div class="table-row"><div class="table-cell-details tight">{{ label_last_offline }}: &nbsp;</div><div class="table-cell-details">{{ server.last_offline }} {{ server.last_offline_duration }}</div></div>
 				</div>
 			</td>
 		</tr>
diff --git a/src/templates/default/module/server/server/view.tpl.html b/src/templates/default/module/server/server/view.tpl.html
index a9423f7e..af5224ea 100644
--- a/src/templates/default/module/server/server/view.tpl.html
+++ b/src/templates/default/module/server/server/view.tpl.html
@@ -49,6 +49,10 @@
 			<td>{{ label_last_online }}:</td>
 			<td>{{ last_online }}</td>
 		</tr>
+		<tr>
+			<td>{{ label_last_offline }}:</td>
+			<td>{{ last_offline }} {{ last_offline_duration }}</td>
+		</tr>		
 		<tr>
 			<td>{{ label_rtime }}:</td>
 			<td>{{ rtime }} s</td>
diff --git a/src/templates/default/module/server/status/index.tpl.html b/src/templates/default/module/server/status/index.tpl.html
index c66cde78..3d31ac69 100644
--- a/src/templates/default/module/server/status/index.tpl.html
+++ b/src/templates/default/module/server/status/index.tpl.html
@@ -16,6 +16,7 @@
 				<div class="entity" onclick="window.location.href='{{ server.url_view|raw }}'">
 					<h2>{{ server.label }}</h2>
 					<p>{{ label_last_online }}: {{ server.last_online_nice }}</p>
+					<p>{{ label_last_offline }}: {{ server.last_offline_nice }} {{ server.last_offline_duration_nice }}</p>
 					<p>{{ label_rtime }}: {{ server.rtime }}s</p>
 				</div>
 			</div>
@@ -33,11 +34,13 @@
 									<div class="table-body">
 										<div class="table-row"><div class="table-cell-details tight">{{ label_last_online }}: &nbsp;</div><div class="table-cell-details">{{ server.last_online_nice }}</div></div>
 										<div class="table-row"><div class="table-cell-details tight">{{ label_last_check }}: &nbsp;</div><div class="table-cell-details">{{ server.last_checked_nice }}</div></div>
+										<div class="table-row"><div class="table-cell-details tight">&nbsp;</div><div class="table-cell-details">&nbsp;</div></div>
 									</div>
 								</div>
 							</td>
 							<td class="{{ server.class_warning }} hidden-phone">{{ label_last_online }}: {{ server.last_online_nice }}</td>
 							<td class="{{ server.class_warning }} hidden-phone">{{ label_last_check }}: {{ server.last_checked_nice }}</td>
+							<td class="{{ server.class_warning }} hidden-phone"></td>
 						</tr>
 					{% endfor %}
 					{% for server in servers_online %}
@@ -46,11 +49,13 @@
 								<div class="visible-phone">
 									<div class="table-body">
 										<div class="table-row"><div class="table-cell-details tight">{{ label_last_online }}: &nbsp;</div><div class="table-cell-details">{{ server.last_online_nice }}</div></div>
+										<div class="table-row"><div class="table-cell-details tight">{{ label_last_offline }}: &nbsp;</div><div class="table-cell-details">{{ server.last_offline_nice }} {{ server.last_offline_duration_nice }}</div></div>
 										<div class="table-row"><div class="table-cell-details tight">{{ label_rtime }}: &nbsp;</div><div class="table-cell-details">{{ server.rtime }}</div></div>
 									</div>
 								</div>
 							</td>
 							<td class="hidden-phone">{{ label_last_online }}: {{ server.last_online_nice }}</td>
+							<td class="hidden-phone">{{ label_last_offline }}: {{ server.last_offline_nice }} {{ server.last_offline_duration_nice }}</td>
 							<td class="hidden-phone">{{ label_rtime }}: {{ server.rtime }}s</td>
 						</tr>
 					{% endfor %}