eventDrop: (dropInfo:EventDropArg) => {
        const start = moment(dropInfo.event.startStr).toDate();
        const wp = dropInfo.event.extendedProps.workPackage as WorkPackageResource;
        if (!wp.ignoreNonWorkingDays && (this.weekdayService.isNonWorkingDay(start) || this.workPackagesCalendar.isNonWorkingDay(start))) {
          this.toastService.addError(this.text.cannot_drag_to_non_working_day);