Question

I am rendering out a DateTime field from my view model into two separate form fields (Date and Time). I have this line of code in my view:

@Html.TextBox("EndTime.Date", Model.EndTime.ToShortDateString())

which renders as:

<input data-val="true" data-val-date="The field Date must be a date." 
 data-val-required="The Date field is required." id="StartTime_Date"
 name="StartTime.Date" type="text" value="29/09/2012">

• Why is this input field having the data-* attributes added to it?
• Why does it even think it is a date?

An interesting side-effect of this unexpected validation is it causes the field to be validated as a date (which is what I want by coincidence), but jquery is deciding to use the wrong date format so I get the error:

“The field Date must be a date.”

---

UPDATE:
Turns out the “wrong date format” error was caused by a bug in Chrome. Because the JQuery Validation library validates a date by creating a new Date(), and because Chrome always seems to parse dates as en-US (totally ignoring the locale /language settings) it was failing when I put in en-UK dates.

Answer 1

Why is this input field having the data-* attributes added to it?

Because you have enabled unobtrusive validation in your application. As default, the MVC validation system enables client-side validations of both required & datatype for value types(integer, datetime).

Why does it even think it is a date?

When you pass a string to the Html.TextBox helper method it checks if the Model contains any property with that name and in your case the Model has a property with name EndTime and which is of type DateTime.

You are passing EndTime.Date that still represents the type DateTime(DateTime has a property Date which is of type DateTime contains only the date component) and so the two validations are enabled by MVC.

I would suggest you two create two different properties to store the date and time.