fix: use selected duration when checking for conflicts for new bookings (#10713)

packages/features/bookings/lib/handleNewBooking.ts

@@ -367,6 +367,7 @@ async function ensureAvailableUsers(
   }
 ) {
   const availableUsers: IsFixedAwareUser[] = [];
+  const duration = dayjs(input.dateTo).diff(input.dateFrom, 'minute');
 
   const originalBookingDuration = input.originalRescheduledBooking
     ? dayjs(input.originalRescheduledBooking.endTime).diff(
@@ -411,10 +412,10 @@ async function ensureAvailableUsers(
         // running at the first unavailable time.
         let i = 0;
         while (!foundConflict && i < allBookingDates.length) {
-          foundConflict = checkForConflicts(bufferedBusyTimes, allBookingDates[i++], eventType.length);
+          foundConflict = checkForConflicts(bufferedBusyTimes, allBookingDates[i++], duration);
         }
       } else {
-        foundConflict = checkForConflicts(bufferedBusyTimes, input.dateFrom, eventType.length);
+        foundConflict = checkForConflicts(bufferedBusyTimes, input.dateFrom, duration);
       }
     } catch {
       log.debug({