date pick format

  pacakage: intl: ^0.17.0
  pacakage: syncfusion_flutter_datepicker: ^20.3.49
  
  String _selectedDate = '';
  String _dateCount = '';
  String _range = '';
  String _rangeCount = '';
  DateRangePickerController dateRangePickerController =
      DateRangePickerController();
      
      

  void _onSelectionChanged(DateRangePickerSelectionChangedArgs args) {
    setState(() {
      if (args.value is PickerDateRange) {
        _range = '${DateFormat('dd/MM/yyyy').format(args.value.startDate)} -';
        // ignore: lines_longer_than_80_chars
        ' ${DateFormat('dd/MM/yyyy').format(args.value.endDate ?? args.value.startDate)}';
        Navigator.pop(context);
      } else if (args.value is DateTime) {
        _selectedDate = args.value.toString();
        var date = DateTime.parse(_selectedDate).toLocal();
        var inputFormat = DateFormat('yyyy-MM-dd HH:mm');
        var inputDate =
            inputFormat.parse(date.toString()); // <-- dd/MM 24H format

        ///if 25/11/2020 12:00 AM show then write('dd/MM/YYYY hh:mm a')
        // var outputFormat = DateFormat('dd/MM/yyyy hh:mm a');
        var outputFormat = DateFormat('dd MMM, ');
        var outputDate = outputFormat.format(inputDate);
        var outputFormatDay = DateFormat.E().format(inputDate);
        // print(outputDate);
        // print(outputFormatDate);
        
        OUTPUT::--- 18 Jan, Wed

        _datePickController.text = outputDate + outputFormatDay;
        Navigator.pop(context);
      } else if (args.value is List<DateTime>) {
        _dateCount = args.value.length.toString();
        Navigator.pop(context);
      } else {
        _rangeCount = args.value.length.toString();
        Navigator.pop(context);
      }
    });
  }
  
 -------------------------------------------------------------------------------------------------------------------------------
 
 SfDateRangePicker(
          onSelectionChanged: _onSelectionChanged,
          controller: dateRangePickerController,
          selectionMode: DateRangePickerSelectionMode.single,
          initialDisplayDate: DateTime.now(),
          navigationMode: DateRangePickerNavigationMode.snap,
          selectionColor: ColorUtils.secondaryColor,
        ),