Want to pass null value for Datetime

DateTime datatype shouldn't be null. Instead use DateTime.Minvalue which stores the minimum value.

A value type such as System.DataTime cannot accept null or DBNull value. This type should also have a value.

There is a popular method of using DateTime.MinValue. This is nothing like yes another programming fraud. MinValue represents the time point of 00:00:00.0000000, January 1, 0001. Why on Earth this time should be considered as invalid (while a time of one millisecond later is valid)?!

I think there is only one decent solution: use a nullable type derived from DataTime.

System.DataTime? MyDateTime;

//MyDateTime can be assigned to null or vSystem.DateTime value:
MyDateTime = null; //if database returns DBNull
//...
MyDateTime = DateTime.Now; //or any valid valid System.DateTime value

For more information on nullable types, see http://msdn.microsoft.com/en-us/library/1t3y8s4s.aspx[^].
A primary purpose of introduction of nullable types was handling of the situations similar to the one described in the present Question.

—SA

string mindate = "01/01/1900";
DateTime? value = Convert.ToDateTime(mindate);
cmd.Parameters.AddWithValue("@start_date", string.IsNullOrEmpty(start_date) ? value  : Convert.ToDateTime(start_date));


if DateTime? value=null; using
value= null means it gets default 
That is value= 1/1/0001 12:00:00 AM 
but SqlDateTime Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM.

so SqlDateTime overflow occurs

so that DateTime? value=null not working

But If you Using DateTime2 to design table 
it accept value= 1/1/0001 12:00:00 AM 

You can use something like.

<code>
DateTime date = dbval == DBNull.Value ? DateTime.MinValue : Convert.ToDateTime(dbval);
</code>

pass Datetime as yourDate.MinDate

Refer
http://www.dotnetperls.com/nullable-datetime[^]

You can take nullable date time.

For example
DateTime? dateVariable = null;