diff --git a/frontend/src/app/statistics/taskgroup-activity/simple-activity-diagram/simple-activity-diagram.component.ts b/frontend/src/app/statistics/taskgroup-activity/simple-activity-diagram/simple-activity-diagram.component.ts
index dc20fb4..6a07f82 100644
--- a/frontend/src/app/statistics/taskgroup-activity/simple-activity-diagram/simple-activity-diagram.component.ts
+++ b/frontend/src/app/statistics/taskgroup-activity/simple-activity-diagram/simple-activity-diagram.component.ts
@@ -39,7 +39,7 @@ export class SimpleActivityDiagramComponent {
 
   createDateRange(): Date[] {
     const dates: Date[] = [];
-    for (let i: number = 1; i <= 31; i++) {
+    for (let i: number = 1; i <= 30; i++) {
 
       dates.push(moment().subtract(30-i, 'd').toDate());
     }