diff --git a/src/main/resources/public/app/components/teacherCard.component.js b/src/main/resources/public/app/components/teacherCard.component.js
index c5f17a6..36386e0 100644
--- a/src/main/resources/public/app/components/teacherCard.component.js
+++ b/src/main/resources/public/app/components/teacherCard.component.js
@@ -115,6 +115,11 @@ function EditGroupDialogController($scope, $mdDialog, EducationService, group, G
         }
     });
 
+    const groupPeriods = [];
+    for(const p of group.period){
+        groupPeriods[p] = true;
+    }
+
     $scope.vm = {
         formData: {
             groupName: group.groupName,
@@ -127,9 +132,10 @@ function EditGroupDialogController($scope, $mdDialog, EducationService, group, G
                     id: group.course.education.id
                 }
             },
-            period: group.period,
+            period: groupPeriods,
         },
     };
+
     $scope.usersChange = (val) => {
         $scope.vm.formData.users = val;
     };
@@ -151,6 +157,12 @@ function EditGroupDialogController($scope, $mdDialog, EducationService, group, G
         if (Object.keys($scope.vm.formData.period).length !== 0 && $scope.vm.formData.users.length !== 0 &&
             $scope.vm.formData.groupName != null && $scope.vm.formData.startYear != null && $scope.vm.formData.endYear != null &&
             $scope.vm.formData.course != null) {
+
+            const periods = [];
+            for(const p in $scope.vm.formData.period) {
+                if($scope.vm.formData.period[p] === true) periods.push(p);
+            }
+            $scope.vm.formData.period = periods;
             GroupService.editGroup($scope.vm.formData, $scope.group.id);
             $scope.showSimpleToast();
             $scope.hide();
diff --git a/src/main/resources/public/app/js/groups.js b/src/main/resources/public/app/js/groups.js
index a8ea415..b12f4ea 100644
--- a/src/main/resources/public/app/js/groups.js
+++ b/src/main/resources/public/app/js/groups.js
@@ -27,10 +27,10 @@ app.controller('TeacherGroupsCtrl', function ($scope, $mdDialog, UserService, Gr
                 $scope.closed = [];
                 $scope.pending = [];
                 $scope.open = [];
-                
-                angular.forEach($scope.teacherGroupList, function(value, key) {
-                    GroupService.getGradingStatus(value.id).then(function(response){
-                        switch(response.data.status){
+
+                angular.forEach($scope.teacherGroupList, function (value, key) {
+                    GroupService.getGradingStatus(value.id).then(function (response) {
+                        switch (response.data.status) {
                             case "CLOSED":
                                 $scope.closed.push(value);
                                 break;
@@ -109,6 +109,7 @@ app.controller('TeacherGroupsCtrl', function ($scope, $mdDialog, UserService, Gr
             if (Object.keys($scope.vm.formData.period).length !== 0 && $scope.vm.formData.users.length !== 0 &&
                 $scope.vm.formData.groupName != null && $scope.vm.formData.startYear != null && $scope.vm.formData.endYear != null &&
                 $scope.vm.formData.course != null) {
+                $scope.vm.formData.period = Object.keys($scope.vm.formData.period);
                 GroupService.createGroup($scope.vm.formData);
                 $scope.showSimpleToast();
                 $scope.hide();