It's not the SQL part that is the problem - you return the value from SQL into the appropriate .NET class: DateTime - so the time part is automatically set to 0, or midnight. DateTime always contains a time element (since it is a number of milliseconds since an arbitrary point in the past).
So what you need to do is stop using the default ToString implementation to display your date value as it always include the time.
myTextBox.Text = myDateTime.ToString("MM/dd/yyyy");
Will do it, or look at this:
Formatting a DateTime for display - format string description