jquery uk date validation problem. "20/05/2019 is not a valid value for DateTime"

Question

I have has an issue trying to get jquery validation to accept a uk formatted date for a while now, basically when I add @Scripts.Render("~/bundles/jqueryval") to my section, the validation does not recognise my date field as having a valid value.

I have followed this guide (http://www.ablogaboutcoding.com/2017/08/12/mvc-uk-date-issues/) to try to solve the problem but have ran into an issue that I am hoping someone can help with. This issue is when the ModelBinder tries to convert the uk value to the DateTime. Code below:

I have tried converting the value to a DateTime (see var date2) & this will work with uk dates but I cannot then apply the correct culture.

Model Binder:

 public class NullableDateTimeModelBinder : IModelBinder
    {
        public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
        {
            var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);

            if (value == null || string.IsNullOrWhiteSpace(value.AttemptedValue))
                return null;           

            bindingContext.ModelState.SetModelValue(bindingContext.ModelName, value);

            try
            {
                var date2 = Convert.ToDateTime(value.AttemptedValue); 

                var date = value.ConvertTo(typeof(DateTime), Thread.CurrentThread.CurrentUICulture);                

                return date;
            }
            catch (Exception ex)
            {
                bindingContext.ModelState.AddModelError(bindingContext.ModelName, ex);
                return null;
            }
        }
    }

Fails at var date. Inner Exception = "String was not recognized as a valid DateTime". Message = "20/05/2019 is not a valid value for DateTime".

If I enter a date of "10/05/2019", I do not get an exception as it can be converted to an American date.

Model:

     [Required(ErrorMessage = "Enter the planned start date of the project")]
            [DataType(DataType.Date)]       
            [Column(TypeName = "DATE")]
            public DateTime? PlannedStartDate { get; set; }

View:

<div class="form-inline">
        <div class='input-group date mydatepicker'>
            @Html.TextBoxFor(m => m.FormData.PlannedStartDate, new { title = "Planned Start Date", @class = "form-control", placeholder = "dd/mm/yyyy" })

            <span class="input-group-addon">
                <span class="glyphicon glyphicon-calendar"></span>
            </span>
        </div>
    </div>

Scripts:

$(document).on('click', '#ajaxCreate2', function () {
var $form = $('#form0')
            .validate({
                rules: {
                    FormData_PlannedStartDate: {
                        dateITA: true
                    }
                }
            });
            if ($form.valid()) {           

            $.ajax({

                async: false,             
                type: 'POST',
                url: 'ajaxCreate',
                datatype: "json",
                data:               
                        JSON.stringify($('#form0').serialize()),                      

                success: function (data) {

                }
            });
            } else {
                var validator = $('#form0').validate();

                $.each(validator.errorMap, function (index, value) {


                    $(function () {
                        var a = value;
                        if (a != '')
                            toastr.error("", a);              

                    })   

                });

            }
        });

Answer 1

You're going to have to be specific about your DateTime conversions and use a specific culture, instead of relying on the server default culture.

DateTime.Parse("20/05/2019", CultureInfo.GetCultureInfo("en-gb"))

This will correctly parse UK formatted (dd/MM/yyyy) dates.