diff --git a/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java b/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java
index eac95c6..d77bdfc 100644
--- a/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java
+++ b/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java
@@ -89,4 +89,13 @@ public class Groups {
     public void setCourseId(Course courseId) {
         this.courseId = courseId;
     }
+
+    public String getTimeString() {
+        int minutes = this.getTime() % 60;
+        String minutesString = Integer.toString(minutes);
+        if (minutes < 10) {
+            minutesString = "0" + minutesString;
+        }
+        return String.format("%o.%s", this.getTime() / 60, minutesString);
+    }
 }
\ No newline at end of file
diff --git a/restservice/src/main/java/com/plannaplan/controllers/GroupController.java b/restservice/src/main/java/com/plannaplan/controllers/GroupController.java
index bb61c45..6d10216 100644
--- a/restservice/src/main/java/com/plannaplan/controllers/GroupController.java
+++ b/restservice/src/main/java/com/plannaplan/controllers/GroupController.java
@@ -1,6 +1,5 @@
 package com.plannaplan.controllers;
 
-import java.security.acl.Group;
 import java.util.ArrayList;
 import java.util.Dictionary;
 import java.util.Hashtable;
@@ -32,7 +31,7 @@ public class GroupController {
             Dictionary<String, Object> group = new Hashtable<>();
             group.put("id", g.getId());
             group.put("day", g.getDay().label + 1);
-            group.put("time", String.format("%o.%o", g.getTime() / 60, g.getTime() % 60));
+            group.put("time", g.getTimeString());
             group.put("lecturer", g.getLecturer().toString());
             group.put("room", g.getRoom());
             group.put("capacity", g.getCapacity());