diff --git a/openslides/core/static/css/app.css b/openslides/core/static/css/app.css
index 32f6aa0e0..d278a6923 100644
--- a/openslides/core/static/css/app.css
+++ b/openslides/core/static/css/app.css
@@ -458,6 +458,10 @@ img {
     padding-right: 10px;
 }
 
+.col2 .countdown_timer.negative {
+    color: #CC0000;
+}
+
 .col2 .notNull {
     color: red;
     font-weight: bold;
diff --git a/openslides/core/static/js/core/base.js b/openslides/core/static/js/core/base.js
index f850e8cd7..59201377e 100644
--- a/openslides/core/static/js/core/base.js
+++ b/openslides/core/static/js/core/base.js
@@ -333,25 +333,22 @@ angular.module('OpenSlidesApp.core', [
     function () {
         return function (totalseconds) {
             var time;
-            var total = Math.abs(totalseconds);
-            if (parseInt(totalseconds)) {
-                var hh = Math.floor(total / 3600);
-                var mm = Math.floor(total % 3600 / 60);
-                var ss = Math.floor(total % 60);
-                var zero = "0";
-                // Add leading "0" for double digit values
-                hh = (zero+hh).slice(-2);
-                mm = (zero+mm).slice(-2);
-                ss = (zero+ss).slice(-2);
-                if (hh == "00")
-                    time =  mm + ':' + ss;
-                else
-                    time = hh + ":" + mm + ":" + ss;
-                if (totalseconds < 0)
-                    time = "-"+time;
-            } else {
-                time = "--:--";
-            }
+            // floor returns the largest integer of the absolut value of totalseconds
+            var total = Math.floor(Math.abs(totalseconds));
+            var hh = Math.floor(total / 3600);
+            var mm = Math.floor(total % 3600 / 60);
+            var ss = Math.floor(total % 60);
+            var zero = "0";
+            // Add leading "0" for double digit values
+            hh = (zero+hh).slice(-2);
+            mm = (zero+mm).slice(-2);
+            ss = (zero+ss).slice(-2);
+            if (hh == "00")
+                time =  mm + ':' + ss;
+            else
+                time = hh + ":" + mm + ":" + ss;
+            if (totalseconds < 0)
+                time = "-"+time;
             return time;
         };
     }
diff --git a/openslides/core/static/templates/core/slide_countdown.html b/openslides/core/static/templates/core/slide_countdown.html
index 17949e128..6fcb54ad3 100644
--- a/openslides/core/static/templates/core/slide_countdown.html
+++ b/openslides/core/static/templates/core/slide_countdown.html
@@ -1,6 +1,6 @@
 <div ng-controller="SlideCountdownCtrl">
   <div ng-if="visible">
-    <div class="countdown well" style="margin-top: calc({{index}}*100px);">
+    <div class="countdown well" style="margin-top: calc({{index}}*100px);" ng-class="{ 'negative': seconds < 0 }">
       {{ seconds | osSecondsToTime}}
       <div class="description">{{ description }}</div>
     </div>