diff --git a/frontend/src/components/Contributions/ContributionForm.spec.js b/frontend/src/components/Contributions/ContributionForm.spec.js
index 8f35948f9..3af716d36 100644
--- a/frontend/src/components/Contributions/ContributionForm.spec.js
+++ b/frontend/src/components/Contributions/ContributionForm.spec.js
@@ -198,6 +198,75 @@ describe('ContributionForm', () => {
           })
         })
       })
+
+      describe('date with the 31st day of the month', () => {
+        describe('same month', () => {
+          beforeEach(async () => {
+            await wrapper.setData({
+              maximalDate: new Date('2022-10-31T00:00:00.000Z'),
+              form: { date: new Date('2022-10-31T00:00:00.000Z') },
+            })
+          })
+
+          describe('minimalDate', () => {
+            it('has "2022-09-01T00:00:00.000Z"', () => {
+              expect(wrapper.vm.minimalDate.toISOString()).toBe('2022-09-01T00:00:00.000Z')
+            })
+          })
+
+          describe('isThisMonth', () => {
+            it('has true', () => {
+              expect(wrapper.vm.isThisMonth).toBe(true)
+            })
+          })
+        })
+      })
+
+      describe('date with the 28th day of the month', () => {
+        describe('same month', () => {
+          beforeEach(async () => {
+            await wrapper.setData({
+              maximalDate: new Date('2023-02-28T00:00:00.000Z'),
+              form: { date: new Date('2023-02-28T00:00:00.000Z') },
+            })
+          })
+
+          describe('minimalDate', () => {
+            it('has "2023-01-01T00:00:00.000Z"', () => {
+              expect(wrapper.vm.minimalDate.toISOString()).toBe('2023-01-01T00:00:00.000Z')
+            })
+          })
+
+          describe('isThisMonth', () => {
+            it('has true', () => {
+              expect(wrapper.vm.isThisMonth).toBe(true)
+            })
+          })
+        })
+      })
+
+      describe('date with 29.02.2024 leap year', () => {
+        describe('same month', () => {
+          beforeEach(async () => {
+            await wrapper.setData({
+              maximalDate: new Date('2024-02-29T00:00:00.000Z'),
+              form: { date: new Date('2024-02-29T00:00:00.000Z') },
+            })
+          })
+
+          describe('minimalDate', () => {
+            it('has "2024-01-01T00:00:00.000Z"', () => {
+              expect(wrapper.vm.minimalDate.toISOString()).toBe('2024-01-01T00:00:00.000Z')
+            })
+          })
+
+          describe('isThisMonth', () => {
+            it('has true', () => {
+              expect(wrapper.vm.isThisMonth).toBe(true)
+            })
+          })
+        })
+      })
     })
 
     describe('set contrubtion', () => {
diff --git a/frontend/src/components/Contributions/ContributionForm.vue b/frontend/src/components/Contributions/ContributionForm.vue
index 71593f2b1..3884fd5b4 100644
--- a/frontend/src/components/Contributions/ContributionForm.vue
+++ b/frontend/src/components/Contributions/ContributionForm.vue
@@ -131,10 +131,8 @@ export default {
   },
   computed: {
     minimalDate() {
-      // sets the date to the 1st of the previous month
-      let date = new Date(this.maximalDate) // has to be a new object, because of 'setMonth' changes the objects date
-      date = new Date(date.setMonth(date.getMonth() - 1))
-      return new Date(date.getFullYear(), date.getMonth(), 1)
+      const date = new Date(this.maximalDate)
+      return new Date(date.setMonth(date.getMonth() - 1, 1))
     },
     disabled() {
       return (