what is ApplyFormatInEditMode viewmodel mvc?

If you want to validate the input using the format you've specified you'll likely have to create your own ValidationAttribute, and use DateTime.ParseExact() to attempt to ensure it meets the format you're expecting. The only draw back is it will not have an accompanying client side validation logic unless you write it.

 

I have not tested this thuroughly, but it should give you a start.

 

public class DateTimeFormatAttribute : ValidationAttribute {

public int Format { get; set; }

public override bool IsValid(object value)

{ if (value == null)

return true;

DateTime val;

try {

val = DateTime.ParseExact(value.ToString(), Format, null);

} catch(FormatException)

{ return false; }

//Not entirely sure it'd ever reach this, but I need a return statement in all codepaths return val != DateTime.MinValue; } }

 

Then it's just a matter of using it. [DateTimeFormat(Format = "dd MMM yyyy")]