diff --git a/src/common/dayjs.ts b/src/common/dayjs.ts
index 9d0c1d0..633b72c 100644
--- a/src/common/dayjs.ts
+++ b/src/common/dayjs.ts
@@ -1,13 +1,15 @@
 import 'dayjs/locale/nl'
 
 import * as dayjs from 'dayjs'
+import * as customParseFormat from 'dayjs/plugin/customParseFormat'
 import * as isSameOrBefore from 'dayjs/plugin/isSameOrBefore'
 import * as timezone from 'dayjs/plugin/timezone'
 import * as utc from 'dayjs/plugin/utc'
 
+dayjs.extend(customParseFormat)
 dayjs.extend(isSameOrBefore)
-dayjs.extend(utc)
 dayjs.extend(timezone)
+dayjs.extend(utc)
 dayjs.locale('nl')
 
 dayjs.tz.setDefault('Europe/Amsterdam')
@@ -32,8 +34,9 @@ export const convertDateRangeStringToObject = ({
 
 const dayjsTz = (
 	date?: string | number | Date | dayjs.Dayjs | null | undefined,
+	format?: string,
 ) => {
-	return dayjs(date).tz()
+	return dayjs(date, format).tz()
 }
 
 export default dayjsTz
diff --git a/src/waitingList/service.ts b/src/waitingList/service.ts
index 0c383ac..d53ed29 100644
--- a/src/waitingList/service.ts
+++ b/src/waitingList/service.ts
@@ -64,7 +64,14 @@ export class WaitingListService {
 
 	private async handleWaitingListEmail(email: Email) {
 		const { date, startTime } = this.getWaitingListDetails(email)
-		const dateRangeStart = dayjs(`${date} ${startTime}`)
+		const dateRangeStart = dayjs(`${date} ${startTime}`, 'YYYY-MM-DD HH:mm')
+		if (!dateRangeStart.isValid()) {
+			this.loggerService.error('Invalid date parsed from email', {
+				date,
+				startTime,
+			})
+			return
+		}
 		const reservations = await this.reservationsService.getByDateOnWaitingList(
 			dateRangeStart,
 		)