diff --git a/doc/80-Upgrading.md b/doc/80-Upgrading.md
index c313fb485..5cf22e0c9 100644
--- a/doc/80-Upgrading.md
+++ b/doc/80-Upgrading.md
@@ -3,6 +3,16 @@
 Specific version upgrades are described below. Please note that upgrades are incremental. An upgrade from
 v2.6 to v2.8 requires to follow the instructions for v2.7 too.
 
+## Upgrading to Icinga Web 2.13
+
+**Breaking changes**
+
+* The following columns of the `Servicestatus` table, which previously displayed the date time (string) as a fetched value, now display the unix timestamp to support relative time filters:
+    * `service_last_time_ok`
+    * `service_last_time_unknown`
+    * `service_last_time_warning`
+    * `service_last_time_critical`
+
 ## Upgrading to Icinga Web 2.12.2
 
 **Framework changes affecting third-party code**
diff --git a/modules/monitoring/library/Monitoring/Backend/Ido/Query/ServicestatusQuery.php b/modules/monitoring/library/Monitoring/Backend/Ido/Query/ServicestatusQuery.php
index fafa03be8..b40ae10a8 100644
--- a/modules/monitoring/library/Monitoring/Backend/Ido/Query/ServicestatusQuery.php
+++ b/modules/monitoring/library/Monitoring/Backend/Ido/Query/ServicestatusQuery.php
@@ -202,10 +202,10 @@ class ServicestatusQuery extends IdoQuery
             'service_last_notification'                 => 'UNIX_TIMESTAMP(ss.last_notification)',
             'service_last_state_change'                 => 'UNIX_TIMESTAMP(ss.last_state_change)',
             'service_last_state_change_ts'              => 'ss.last_state_change',
-            'service_last_time_critical'                => 'ss.last_time_critical',
-            'service_last_time_ok'                      => 'ss.last_time_ok',
-            'service_last_time_unknown'                 => 'ss.last_time_unknown',
-            'service_last_time_warning'                 => 'ss.last_time_warning',
+            'service_last_time_critical'                => 'UNIX_TIMESTAMP(ss.last_time_critical)',
+            'service_last_time_ok'                      => 'UNIX_TIMESTAMP(ss.last_time_ok)',
+            'service_last_time_unknown'                 => 'UNIX_TIMESTAMP(ss.last_time_unknown)',
+            'service_last_time_warning'                 => 'UNIX_TIMESTAMP(ss.last_time_warning)',
             'service_long_output'                       => 'ss.long_output',
             'service_max_check_attempts'                => 'ss.max_check_attempts',
             'service_modified_service_attributes'       => 'ss.modified_service_attributes',