@dlatikay! based on your first comment i changed the datatype from DateTime to string and it worked.
dTable.Columns.Add("created_on", typeof(string));
When the datatype is DateTime,the result is coming as expected,but on insertion to sql the value is changing.Now, while iam sending the value as string to sql,it is converting that string to DateTime and it worked.
Thank you all for your responses.
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