Format dates in a Gridview column
To format a gridview column to display dates properly , two properties needs to be changed, the DateFormatString property and the HTML encode property. After setting the DateFormatString the HTMLEncode property should be set to false. For Example :
<asp:BoundField DataField="RegistrationDate" DataFormatString="{0:MM/dd/yyyy}" HeaderText="Date"
HtmlEncode="False" SortExpression="RegistrationDate" />