diff --git a/components/wizard/context/validationError.ts b/components/wizard/context/validationError.ts
index 6153d99..121b4e8 100644
--- a/components/wizard/context/validationError.ts
+++ b/components/wizard/context/validationError.ts
@@ -1,5 +1,16 @@
+import { VALIDATION_ERRORS } from '../../../db/enums'
+
 interface ValidationErrors {
-  [key: string]: { properties: { message: string } }
+  [key: string]: { properties: { message: string }; kind: string }
+}
+
+function getDefinedValidationMessage(kind: string) {
+  switch (kind) {
+    case VALIDATION_ERRORS.AT_LEAST_ONE_DAY_BOOKED:
+      return 'Mindestens ein angefragter Tag ist nicht mehr verfügbar'
+    default:
+      return null
+  }
 }
 
 export class ValidationError extends Error {
@@ -16,9 +27,12 @@ export class ValidationError extends Error {
   }
 
   get message() {
-    return Object.entries<{ properties: { message: string } }>(this.errors)
+    return Object.entries<{ properties: { message: string }; kind: string }>(
+      this.errors
+    )
       .map(([_key, value]) => {
-        return `${value?.properties?.message}`
+        const validationMessage = getDefinedValidationMessage(value.kind)
+        return validationMessage || `${value?.properties?.message}`
       })
       .join(',')
   }
diff --git a/db/booking.ts b/db/booking.ts
index fd5f131..731ce7f 100644
--- a/db/booking.ts
+++ b/db/booking.ts
@@ -4,7 +4,8 @@ import { dateFormatBackend, getDays, nowInTz } from '../helpers/date'
 
 import { Bill } from './bill'
 import { Booker } from './booker'
-import { BOOKING_STATUS } from './enums'
+import { BOOKING_STATUS, VALIDATION_ERRORS } from './enums'
+import { getBookedDays } from './index'
 
 export interface Booking {
   uuid: string
@@ -71,6 +72,19 @@ const BookingSchema = new mongoose.Schema<BookingDocument>(
     days: {
       type: [String],
       required: true,
+      validate: {
+        validator: async function (days: string[]) {
+          const bookedDays = await getBookedDays()
+
+          const doubleBookedDays = days.filter((day: string) =>
+            bookedDays.includes(day)
+          )
+          return doubleBookedDays.length === 0
+        },
+        message: (props: { value: string[] }) =>
+          `At least one day is of ${props.value.join(',')} is already booked`,
+        type: VALIDATION_ERRORS.AT_LEAST_ONE_DAY_BOOKED,
+      },
     },
     status: {
       type: String,
@@ -89,7 +103,7 @@ const BookingSchema = new mongoose.Schema<BookingDocument>(
   }
 )
 
-BookingSchema.pre('save', function (next) {
+BookingSchema.pre('validate', function (next: () => void) {
   const booking = this as BookingDocument
   booking.days = getDays({
     startDate: new Date(booking.startDate),
diff --git a/db/enums.ts b/db/enums.ts
index da6040c..2e57aba 100644
--- a/db/enums.ts
+++ b/db/enums.ts
@@ -16,3 +16,7 @@ export enum MILAGE_TARIFS {
   EXTERN = 'extern',
   NOCHARGE = 'nocharge',
 }
+
+export enum VALIDATION_ERRORS {
+  AT_LEAST_ONE_DAY_BOOKED = 'atLeastOneDayBooked',
+}
diff --git a/db/index.ts b/db/index.ts
index 9df41ac..d877a4f 100644
--- a/db/index.ts
+++ b/db/index.ts
@@ -1,9 +1,7 @@
 import * as mongoose from 'mongoose'
-import { getYear } from 'date-fns'
 import BookerModel, { Booker } from './booker'
 import BookingModel, { Booking } from './booking'
 import BillModel, { Bill } from './bill'
-import { dateFormatFrontend } from '../helpers/date'
 import { BOOKING_STATUS } from './enums'
 
 let connectedPromise: Promise<typeof mongoose>
@@ -66,20 +64,6 @@ export async function createBooking({
     org,
     destination,
   })
-  const bookedDays = await getBookedDays()
-
-  const doubleBookedDays = booking.days.filter((day: string) =>
-    bookedDays.includes(day)
-  )
-  if (doubleBookedDays.length) {
-    const error = new mongoose.Error.ValidationError(booking.uuid)
-    error.errors.days = new mongoose.Error.ValidatorError(
-      `${doubleBookedDays
-        .map((dateString) => dateFormatFrontend(new Date(dateString)))
-        .join(', ')} schon gebucht`
-    )
-    throw error
-  }
 
   let booker = await BookerModel.findOne({ email }).exec()
   if (!booker) {